My advice: Stick to BB. Pricing for unlimited BB are DEFINITELY CHEAPER den what mobile 3G Internet access is gonna be.
Personally, I stick to my GPRS for very small volumes of data like checking bus schedules, doing small downloads like Handphone Themes, doing movie bookings, etc, etc. Large volumes of data still goes thru my MaxOnline 1500. Not to mention da speed difference is pretty significant.
