I used my Treo with EV-DO constantly. It had Good software installed which meant it was almost always going out to check for new mail. I had a weather application updated every half hour. I checked my GMail on it, which meant a lot of time spent on the browser. I was always going to Wikipedia on it to answer questions that came up in every day conversation. I even talked on it from time to time

I charged it every night, and never once had it die on me while I was using it.