One thing that kills my phone, that I've noticed of late, is that I use a Bluetooth earpiece and that's fine, but once at the office I turn it off and switch my my Touchpad and a pair of stereo headset (BT).
I noticed that the phone, even if not paired with it, would keep trying to pair with it, possibly because the headset is capable of being linked (paired) to multiple devices and might be sending some sort of nudge.
So I now turn the BT off the phone too.
So with my email account set to check once an hour, with WIFI (network at work and at home) on, after about 7 hours today, my battery is at 87%...
Just for an idea of low power usage.
Other days... if I play on it... Galcon for example via the online play, I'll kill my battery down to 40% within an hour or so.
So it's very much linked to usage, like any other phone I've had.
The giant battery would be nice, but not at the expense of not being able to use my Touchstone...
And since I can plug my phone at the office, always set it down on one of my touchstones at home, and have one in the car, plus have a few spare batteries, overall, it's not an issue...
The fact that the Pre2 has a replaceable battery, just adds to it's greatness.