When I heard about the GP2X I was really excited until I read that it uses AA batteries. I never owned a GP32 but was in two minds whether to buy one in the end I didn't for the reason of using AA batteries. When the GP2X was unveiled I was a bit confused as to why gamepark have went down the same path whilst everyone else is using Lithium batteries. I really hope that they bring out a MK2 version with a lithium battery then I'd be the first in line to buy one of these.
With video and emulation I think gamepark are stretching the truth about how long the batteries last.