Thoughts like these are especially prevalent when it comes to the devoted owners of BlackBerrys and iPhones. All too often, the people carrying these smart phones are curious about what one device has that the other lacks. This week, I’m going to save you the trouble and outline some of the personal usage ups and downs to each device.

Because I regularly use both gadgets and am accustomed to their different features, I have included fresh observations from five people who recently switched from BlackBerrys to iPhones. At my request, these people kept track of their impressions, noting the things they missed on their BlackBerrys along with things they preferred on the iPhones. This column isn’t meant to promote one device over the other; rather, it is a summary of some people’s sentiments, combined with my own observations in hopes of enlightening readers. I inevitably left out some differences.

The most outstanding observation from my switch group in favor of the iPhone was an appreciation for its applications, or apps.

They used things like driving directions for the first time because these apps looked and worked better on the iPhone than on the BlackBerry. And they went through a downloading frenzy during which time they found all sorts of apps for the iPhone, such as games, entertainment and those that enhanced business-travel productivity. “Browsing for games. Probably should leave the office now,” said one person’s notes.

Though Research in Motion’s (RIMM) BlackBerrys also run apps (including some of the same ones as for the iPhone), BlackBerry’s App World offers only a little better than 2,000 apps. Apple’s (AAPL) App Store boasts more than 65,000. A shortcut to the App Store ships preloaded on iPhones. BlackBerry App World is preloaded or virtually preloaded by carriers at their discretion, so a shortcut to App World may not be visible.

My switchers were frustrated by the iPhone’s battery life and complained of running low on battery. One person said, “I need to charge my iPhone a couple of times throughout the day which can be inconvenient, especially when traveling. With my BlackBerry I just charged it while I slept and it was good to go for the day.”

Granted, these people were all using the iPhone 3GS and had previously used various models of BlackBerrys that ran on slower networks and had smaller screens—two features that require less battery. Still, worrying about running out of juice is a hassle. One person said his iPhone’s weak battery was a tribute to the fact that he used it more often and for more things than he did the BlackBerry.

The most obvious difference between iPhones and BlackBerrys are the keyboards. The iPhone uses an on-screen keyboard, while the BlackBerry (except the touch-screen Storm model) uses a tactile QWERTY keyboard. As expected, the switchers had trouble using the iPhone keyboard–especially for the first few days. But after about a week, most people in the group had adjusted well to the on-screen keys and the iPhone’s auto-correct feature that fixes mistakes as long as you keep typing rather than stopping to fix an error. One person said, “I was a skeptic, and didn’t think the typing would work for me at all, but it actually hasn’t been too bad.”

Another said typing can be a real challenge at first, but that this could be overcome with a bit of practice.

Several people said they were still able to use their thumbs for iPhone typing as they did on the BlackBerry, though most preferred turning the screen horizontally to do this with slightly larger keys. Some said that they weren’t typing quite as fast as with the BlackBerry’s QWERTY keys but that they weren’t too far off.

The BlackBerry keyboard’s static position below its screen means all letters, numbers and symbols must come solely from pressing those keys; this is done by pressing ALT or Shift keys for numbers and symbols. Some switchers noted that pressing a button to change the iPhone’s on-screen keyboard from letters to capital letters or numbers took a bit longer than on the BlackBerry.

My switchers were ecstatic about using the iPhone’s Safari Web browser. They enthusiastically said searching, browsing and reading were all made much better and more visually pleasing compared with their experiences on the BlackBerry browser.

If you are a BlackBerry user, you know that all received and sent emails are listed on the same screen. The iPhone behaves more like a computer, storing sent emails in a special folder you must back up to open. This takes a little while to get used to.

Some switchers said they wished the iPhone had something like BlackBerry Messenger, the always-on messaging system that works to allow communication between all BlackBerrys.

The iPhone automatically changes its time when you enter a new time zone. BlackBerrys remain set to their home time zone for time stamping all emails with that time–unless you change the time in settings.

RIM prides itself on being able to run multiple applications at once; the iPhone allows this with its own preloaded programs like Mail and Safari, but not with other apps.

One switcher, for example, was frustrated that Pandora, a radio-like app that plays music according to user likes and dislikes, turned off when he opened Mail to read emails while listening to songs.

The BlackBerry’s AC adaptor takes up two power outlet spots, while the small, square iPhone plug occupies only one outlet, making it more versatile and able to charge in more locations.

The iPhone only works on one cellular service: AT&T (T). The BlackBerry is available from Verizon (VZ), AT&T, T-Mobile, Sprint (S) and other carriers. My group used T-Mobile before changing to the iPhone’s AT&T service.

There will always be something on someone else’s device that looks more appealing than the one in your hand.

But the experience of using apps on the iPhone–and the huge selection of apps in the App Store–significantly enhance Apple’s device.

RIM is continually improving its own store, but it needs to move quickly to keep its loyal users contented.

Edited by Walter S. Mossberg

Write to Katherine Boehret at mossbergsolution@wsj.com

At least one smartphone manufacturer is doing something about this. This week, Research In Motion (RIMM) introduced the BlackBerry Pearl Flip 8220, available for $150 with a two-year contract from T-Mobile (DT). This device is the first BlackBerry in a flip phone, or clamshell, form. Like RIM’s mainstream, candy-bar-shaped BlackBerry Pearl, the Flip uses a SureType keyboard, which has condensed keys and relies on predictive text software.

The Pearl Flip uses a SureType keyboard, which takes up less space.

After using the Pearl Flip for a week, I’ve found it to be a stylish messaging device that works well as a comfortable phone. I really liked its exterior screen, which is designed to show previews of incoming messages, saving people the trouble of flipping open the device. It runs on T-Mobile’s slow EDGE network, but has built-in Wi-Fi and the ability to automatically connect to saved, nearby wireless networks.

First-time smartphone buyers will likely find the Pearl Flip to be a good fit. When it flips open, a special hinge drops the top half of the device slightly behind the bottom half, and a handy trackball makes navigation easy. The Flip’s Web browser enables streaming videos that look sharp on its interior screen, and a microSD card slot supports up to 16 gigabytes of memory.

But current BlackBerry owners who want to switch to a device with a more comfortable phone may have trouble adjusting to the Pearl Flip’s SureType keyboard — especially if they’re used to a device with a full QWERTY keyboard. Though the Pearl Flip’s keyboard is a generous size and its keys are flat and easy to press, its SureType design assigns two letters to almost every key, which can be frustrating to use when predictive text guesses a different word than that which is intended.

The Pearl Flip 8220 is RIM’s first flip phone BlackBerry.

The Pearl Flip supports T-Mobile’s Unlimited HotSpot Calling, a service that doesn’t use any minutes on phone calls begun in Wi-Fi zones. Even if a user leaves the Wi-Fi zone in which he or she started a phone conversation, the call passes over to the T-Mobile cellular network without dropping out. This service costs $10 monthly in addition to regular service charges.

When I made calls on the Pearl Flip, friends on the other line noted how crisp and clear our connection sounded. And best of all, the Pearl Flip’s long, clamshell profile was easy to hold and fit snugly and comfortably between my ear and shoulder when I needed two hands to carry things.

BlackBerry’s signature red light blinks in this device’s top corner to indicate new messages. The 1.6-inch exterior screen displays about 25 words (give or take) from newly received emails, instant messages, SMS, MMS, calendar notifications and task reminders. If a message is received from a contact to whom a photo is assigned, that photo also shows up on the external screen to identify the sender. Side buttons let users scroll up or down through these previews.

This display is designed so that the same message being previewed externally will appear on the internal screen as soon as the Pearl Flip is opened. This makes sense because people will want to reply to some emails or read their entire contents after seeing a short preview. But my device didn’t do this at first; instead, the internal screen seemed completely unrelated to the external screen. I finally got this feature to work after my external screen froze and I rebooted the Pearl Flip. RIM said it hadn’t seen this behavior before, and wasn’t sure what had caused it.

The interior screen measures 2.4 inches diagonally and has a resolution of 240×320 pixels, which is a larger, higher resolution screen than most basic cellphones. While using Wi-Fi, I pulled up YouTube.com and watched a video. It played without skipping or stopping while streaming directly from the Web. A higher-resolution video, which was saved to my device, automatically played in horizontal mode so as to take up the entire screen; YouTube videos play vertically, without using the full screen.

Up to 10 email accounts can be set up on the Pearl Flip; I had no problems using Hotmail, .Mac and Gmail accounts. I also signed into AOL Instant Messenger and Google Talk on the Pearl Flip. Along with these messaging programs, ICQ, Windows Live Messenger, Yahoo Messenger and BlackBerry Messenger also come pre-installed and ready to use.

If my Pearl Flip was closed and I remained signed into an instant-messaging client, notifications appeared on the external screen telling me who was sending an IM and what it said. When I opened the device, I was automatically directed to the screen where I could reply to the instant message.

I tested the T-Mobile Unlimited HotSpot Calling feature by starting calls using a Wi-Fi network and then leaving the network’s range. The calls remained steady without dropping or fading, and if I were a paying customer, I wouldn’t have been charged minutes for those calls. Calls that start out of Wi-Fi zones and end in Wi-Fi zones do deduct minutes. My Pearl Flip had no trouble automatically moving from the cellular network to a Wi-Fi network.

All T-Mobile Wi-Fi hotspots, such as at airports or in Starbucks (SBUX), automatically work with the Pearl Flip if you’re registered for the $10 monthly Unlimited Hotspot Calling.

If you’re considering taking the plunge into the always-connected world of smartphones, or if you want a more comfortable phone in your smartphone and don’t mind the quirks of SureType, the Pearl Flip 8220 may be the BlackBerry for you.

– Edited by Walter S. Mossberg

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