I'd like to start off by talking about some of the hardware differences between my BlackBerry and Treo.
The Curve is about a third thinner than my Treo. Eyeballing them both on my desk, the Curve and the Treo are the same width and height, although the Curve is a tiny bit shorter. As far as weight is concerned, the Curve is also a lighter when I'm holding both in my hands, but that so much that I notice a difference when carrying the BlackBerry in a belt case.
I miss the Treo's ringer switch with the BlackBerry. And I like the Treo's keyboard better. The keyboard on the Curve is usable and I am getting along with it OK, however, the Treo keyboard just felt better and more sturdy. The trackball on the BlackBerry is easy to get use to. I like it as much as the 5-way navigator on the Treo because it allows you to hold the device in either hand and use it. That wasn't the case with older BlackBerry devices that only had a scroll wheel on the right side fo the device.
Probably the biggest thing that I miss on the BlackBerry that I used all the time on my Treo is the touch screen. It was really easy to just reach up with a thumb or pointer finger and tap an object on the screen.
Some other welcomed changes wtih the BlackBerry include a standard 3.5mm headphone jack, built-in (assisted) GPS, a mini USB port for charging and data synchronization (which is now the standard on new Palm devices), and a 2.0MP digital camera with a flash. Palm's Treo 755p ships with a 320x320 display. The Curve has a 320x240 display. The difference in display resolution has turned out to not be as big of a deal as I expected it would. I have found both displays easy to read. That said, the BlackBerry has an auto adjusting screen brightness feature where the screen brigthness goes up in well lit rooms making it even easy to ready in a well lit room in the office or at home.
Voice call quality is good on the BlackBerry and I was able to pair my Bluetooth headset with it. The speaker phone option is loud which is good when your home with the kids, however, my not be so good if you are in your office. You will need to adjust the call volume to meet your needs and environment.
All in all, the BlackBerry Curve offers the same hardware features that I like about my Treo. I prefer a full Qwerty keyboard over on screen keyboards like the one found on the Apple iPhone and the multi-function keypad on devices like the BlackBerry Perl. The track ball is as easy to use as the nav pad on the Treo. Both devices fit nicely in my hands, however, I do miss the soft touch paint that Palm has ben using on the Treo 750, 755p, and the newest Sprint Centro smartphones.
For more information about the BlackBerry Curve 8300 series devices, check out Research In Motion's BlackBerry website.