I have the original treo 600 which works just fine...although wish it had BT. I get full internet access via WAP (and a hack from howardchui.com forum). It is perfect for emails and there is even third party software to use as mp3...although iPod or newer phones (eg i also have sony ericsson w810i) are much better as mp3 and camera.

A friend just got the TMO dash and raves about it....but it's a true smartphone, and takes more time to learn, etc. Upside is it's 3G, so gsm and umts (works in korea/japan), has WiFi, so skype will work when near hotspots.