Actually it doesn't take longer than
two or three full days (no nights)
Half day for drawing Half Day for color choice 2 days for lighting.
The reason I get done so slow I take huge as breaks I allready on the first 2 - 3 hours on the empire project. I've took a week away from it.
Theres actually many pixel artist but none but me is in the battleforums branch.
I really don't even count my self as one considering I have only done 1 full peice and about 6 sprites.
Pixel art rarely takes more than 15 hours but people take long breaks because it get annoying at times.
Well I'm off to play Simcity (my curent addiction

)