From my personal experiences with BlackBerrys...
- I loved how the email was pushed through from my email server to the phone. I always got my email super fast and effortlessly. I also enjoyed how it said "Sent from my BlackBerry" at the end of emails sent from my phone. (This option can be removed, I just never did).
- It is a very practical, business oriented phone. Easy to use professional applications on it such as multiple email services, Microsoft products (mobile editions), calender, browsing the internet, even the alarm clock and timer functions were simple.
- All of the apps that you get for the phone come from the BlackBerry App Store, which isn't as good as the Android Market or whatever the iPhones use. There are ways to get the apps direct from the creator's websites and such, but not in a simple way. However, the apps that are available for BB that are created by RIM (the manufacturers of BlackBerrys) are solid and integrate smoothly with the phone. Other app related comments, there are not that many great apps created for the BB, and if they are they usually come out later than for iPhones and Android devices. On the plus side, there is a program coming out for BBs that will allow Android Market apps to be loaded and run on BBs, so its just a matter of time.
- Messaging on BBs is super easy. Having BBM (BalckBerry Messenger) really is super easy to use and communicate with other BB users. Even when not using BBM, the text messaging is simple and effective, no lags or delays in text input or sending time. On the touch screens (Storm, Storm2, Torch) that use user tactile input (your finger) to type on the screen, the SureType input method that BB uses is second to none. (I wish my phone had that now).
- I can't vouch for the other BBs that had physical keypads, I always liked the full touch, but the set up on the phones was easy to use if I was borrowing or messing around on a buddy's BB Bold or Pearl or Curve. The track ball was awful, but the new track pads are super easy and amazing. The newest Bold has a QWERTY keyboard, a track pad, AND a full touch screen. The touch screen makes it AMAZINGLY easy to use the phone for more detailed selecting, easier scrolling, and zooming in.
- The user interface on BBs is super easy to pick up on with a very simple and "duh" kinda factor. Everything just makes sense. The folders are labeled accurately with what they contain, and you can add your own detailed folders for apps and downloads, and files all you want. It isn't hard to learn how to use one. With some other phones (my droidx) I still have to scroll through a lot of the time to find exactly what I need or remember what exactly I was looking for.
-OVERALL, I loved my BB a lot. I had the Storm, and there were just too many flaws in that phone for me to keep up with it. Since I wanted a full touch phone, I switched to a DroidX from Motorola through Verizon. Solid phone, but really aimed at utilizing the phone as a time waster. A lot of childish and gamey apps, I never have my email at my fingertips when I want it ( I have to manually sync it up all the time), and the user interface is just...well, its just lacking something I can't place my finger on. To be honest it's just too much at once. And I did try the DroidPro and it just sucked. The shape of the phone is very difficult to use, the screen is kinda worthless as a touch function on the phone, and the keys seem smaller and easier to press multiples on the keyboard. It's best to go in person and play around with the phones. You'll figure out what is best for you. Just my $0.02 though.