I think electric ATV's/Quads are the future, but they are not quite there yet, needing further improvements in battery or fuel cell technology.

What ever the impact on the deer, I personally hate the noise when driving a conventional quad and find after getting off, it takes ages to get back into "stalking mode"..

That said, I have not used them very much, and when I have, its been for carcass extraction on our larger Red and Fallow deer.