2005 4-runner AWD or 4WD?

Thinking about buying a new 4-runner limited and can't decide between the V6 4wd and the V8 full time awd. I plenty familier with the the 4wd drive trains, but don't have any experience with the full time awd. What kind of long term maintenance can I expect? gas milage? snow/off-road performance? Thanks, I want the V8 power but not sure about the awd.