ye using 5320 xm now..!!!! about battery bakup it is sufficient for me
i use it for browsing net via edge most of the day like about 3-3.5 hrs and 2 hr music with and about 30 min video...!!! still the battery would last a day and a half easily..!! using the phone with least possible display brightness..!!!
and using gprs sucks the battery most!!! and add some data sending and receiving to and from friends