After using Palm devices for 9 years, I switched to a BlackBerry 8830 last week. It has its ups and downs, which have been pointed out here.
Just one word of caution: If you decide to buy a 700p, but it in-person at a store, and make sure you get one with the older 1.06 firmware. The 1.10 maintenance release basically cripples the 700p's data connection. THAT is why I'm sitting here with a Blackberry. I went through 4 700p's in the past month.
Also, don't let them tell you that "a new one with 1.10 won't have these problems, it's only a problem if you install it yourself." A lot of people have fallen for that one.