This is my third day with my Crespo4g. I was coming from a MyTouch3g, which i'd routinely get 3-4 days out of a charge. Day one, I didn't keep track of battery usage, because I was upgrading to 4.04 OTA, installing CM9, etc. Yesterday, my battery life was atrocious. It was down to 30% after about 5 hours, with data turned off for most of the time. I've since turned off most syncing, disabled NFC, and had data enabled (even 4g). Its been off the charger for 7 and half hours, and is at 42%. 4G kept going in and out, because 4g signal is weak at work, and I've used GPS a bit (I've been riding my bike to work, and so had GPS on, with My Tracks logging my trip, when I road to work, then when I went to lunch).
Battery life still leaves to be desired, but I'm much happier with things.