I have gone through so many types of PDA's I couldn't keep up with myself on them. I always like the Palm platform. Touch screen, multi-Media, ease of use....and I felt the Treo was perfect. The problem I had was I used the Treo for E-mail and PIM functions as well as games and video, and I had a Nextel phone thats completely paid for by my company for voice. When Blackberry 7520 came out, I sacrificed the Multi-Media functions to move everything to it so I could have e-mail, PIM, and voice on 1 device. Although I would definitely love to eventually go back to the Treo, the Blackberry has met my needs well. Neither the Treo or the Blackberry has a very good screen for reading an entire E-book, so I'm sticking with my Blackberry for everything, and my Sony Reader for Reading
