[jrockway]

I have the T-Mobile myTouch 3G.

The battery life is a lot better than my old Windows Mobile phone, but I have not gotten anywhere near running low yet, so I can't really comment. My impression is that heavy use does not really run the battery down that quickly.

Performance really depends on what you have in the background. K9 totally kills it for me, because my IMAP server sucks. Google Sky Map and the Market sometimes lag for me. Google Reader can also be very slow. Otherwise, everything is good. I have a task manager installed, but since I stopped using K9, I have not needed it.

It is not a flawless experience, of course, but so much works incredibly well that I don't really care. Google does care about the details (changing colors, syncing contacts), and the third-party apps are really cool. (I forgot to mention Locale above; it's awesome! I never forget to turn my ringer on at home.)