So I got this thing a few months ago, and it's an awesome phone with one exception... the battery only lasts 4 hours (when not even in use).
I was just looking online over the weekend and saw there was a firmware update available. The update improves battery life, but even better it allows for a switch between 3G and 4GLTE, so I can keep the phone in 3G all the time, then switch to 4G when I want to use it.
Awesome, as the 4G antenna is what was killing the battery all along. Now I have a phone that lasts all day without a charge like it should.
So yeah now the thunderbolt totally rules
If you install something like Widgetsoid, you can have instant access to toggling/adjusting all kinds of features to save your battery (and data usage if you don't have an infinite plan). My Droid2 can usually last a couple days or so if I'm not doing much with it.