Picked up the phone after froyo update, and immediately upgraded to 2.2.1 over the air. Noticed that my battery life was absolutely terrible - maybe 6-7 hours tops under normal usage. Turned off all background syncing, kept screen at very low brightness, etc. - no change.
After much googling and research, it turns out that at least under froyo (and maybe eclair - not sure because I've never run eclair for any significant amount of time), the Bravo's default preferred network type is "WCDMA preferred" - which makes the phone prefer and poll for a 3g signal, even in conditions where signal is weak or unavailable. This uses A LOT of power if you run around in areas without excellent 3g coverage.
You can change the default preferred network type, however. You'll need a 3rd party application called "Network" (available in the app market). I switched my phone's preferred network type to "GSM Auto (PRL)" which uses lower powered edge connections to fetch a list of towers the phone could use, then step through that list to make the 3g connection - which eliminates the need for power wasting polling. After this change, my phone went from barely making it through a workday to using only 20-30% of the battery over the course of a workday. Huge difference.
Be aware that even if you've set your phone to something other than the default of "WCDMA preferred" the phone will still default to that setting on boot. You'll need to switch the phone to airplane mode then back to non-airplane mode to get your non-default preferred network setting to stick. You can tell which mode your phone is operating in by looking in Settings > Battery Manager > Cell Standby. If the Cell Standby percentage of power used is well over 40%, and if the Time Without Signal percentage isn't either very low, or a larger but rapidly dropping value - or if TWS isn't altogether missing from that status page, you're likely still on "WCDMA preferred" and losing power very quickly.
Hope this helps someone. This is a great phone if set up correctly - but the default settings really do the product a disservice.
It's also worth noting that the 2.2.1 update is indeed worth all this hassle, besides the just in time compiler and javascript engine speed improvements My biggest concern in switching to this phone was it was only suppoed to capture CIF video (352x288) - 2.2.1 gives you the ability to shoot video with the much higher VGA resolution (640x480), instead.