I bought the 710 previois month. Yeah! The battery capacity is not too high but still for me it stretches upto 14-17 hours during my normal usage that includes:
-Always on EDGE connection.
-Mail sync time set at 30 minutes.
-40 mins to 1 hour surfing.
-20 to 30 mins calling.
-And some minutes of gaming, photo sessions, music etc.
My routine goes a little scheduled up so i can mention exact figures. :P
Each day one or the other person around me is amazed seeing this awesome OS. Love it.