I have a Blackberry Bold 9650 on Verizon. It's OK. The screen is small compared to a Droid, iPhone, etc. Small keypad took some getting use to, but now I can type pretty quickly with it. I've had it for about six months now. Doesn't seem to be as many apps available for BB as there are for Droid, iPhone, etc. This phone also has a very slow boot-up time when the battery is pulled or a new app is installed that requires a reboot. Also, some apps can be real battery-life hogs, such as Weatherbug.
I just upgraded the OS to version 6 last week, and it does seem to be running better than with the previous version. So if you look for a BB make sure it has BB OS 6 or can run BB OS 6.
I had to get another one after two months because the track pad quit working. My wife has the same phone, and almost all of the paint has worn off of her keys. It's probably from her fingernails, but it could be a faulty phone.
If I had to do it over again when I got it last August, I probably would've gotten a Droid 2. Am still thinking of replacing it with a Droid, or now even an iPhone. Only thing holding me back with the iPhone is that I like a tactile keypad. I have an iPod touch, and typing on the touch screen takes some getting used to. If I do go w/iPhone, it won't be soon. I'll wait for the iPhone 5 to be released later this summer.