Just got this for my wife. She's an average user, maybe spend about 1 1/2 hour a day yapping on the phone, and occasional Internet use. She's in a GSM only area and she only burns about 50% of the battery at the end of the day. She syncs and charges the phone every night which I recommend. Looking at this numbers, I would say it would be very easy for a high end user like me to use up the battery in a day specially if being used in UMTS coverage areas. I still have to get mine (the wife comes first of course) but I will post additional comments when I have more info. It's kind of hard to use my wife's 750 since she loves it so much and can't put it down since she got it. She was coming from the frustrations of a Treo 650 and the 750 just ... (continues)
Con: I was only getting 8-10 hours of battery life out of this phone if I was lucky...by the time my evening meetings rolled around the battery was out of juice. I returned it for an 8525 which also was returned; it only worked for 10-12 hours. I finally settled on a BB 8700...works like a charm. I have battery life for several days.