Depends what you mean decent...
The constant or burst rate has an affect on trigger response,where MaH has a more direct affect on longevity of the battery power supplied.
At the weekend I was using 7.4 1200 MaH with 15 constant/25 burst and 7.4 2200 MaH with 35 constant/70 burst.Trying out a new set up the smaller more compact batteries in the stock.With the gun on auto with the larger batteries I could release a 3 shot burst with the slightest flick,there was a noticeable difference when I tried with the smaller batteries.
My gun has a silly h/s motor with a high RoF and the larger batteries are the ones I've always used and there was so much noticeable difference,it is fast compared to others I've tried.
Where the MaH came into it was when I tried to empty a high cap and the battery/power noticeably dropped off,it was audible,but how often do you empty a whole Hi-cap in one go??Perhaps a std gun would see less of a difference.
I found this on the field not in a lab,I'll stick to my big batteries.