I'm fine with the battery life. Coming from a rooted galaxy S2 with pretty efficient ROM, newly replaced battery, half screen brightness, and GPS and Bluetooth usually off... the Alpha is doing better with battery towards the end of the day. This is with near full screen brightness and several tasker profiles that add to battery drain. ATT, stock ROM of course.
That being said, it seems much much better when screen and wifi are off but is no real miser when in use. Occasionally if on the web a couple of hours during the day, I'll recharge before nighttime use (usually plenty of YouTube, Netflix etc). Upside is it charges rather quickly on AC.