About to pull the trigger on either the Atrix or the Charge, and I'd really like to go with the Charge. However, I CANNOT DO WITHOUT 10-12 hours of moderate use on 3G. When I unplug my phone at 4-5pm on a Friday, I need it to last until 2am...sometimes 4am. It's fine if it's only 3G under those circumstances. So, what's the 3G-only runtime for this phone for most people?