I added the Black Tail, just because I'm not familiar with them. I know they are closely related to a Mule Deer, but wasn't sure if their habits are about the same.

I think with a bow, white tail are probably easier to hunt. They are a little easier to pattern and they are more likely to be in an area where you have some cover.
It's tough to get close to a Mule Deer due to the open areas they like to stay in. Don't quite follow a pattern as much as a White Tail.

Rifle, hands down, Mule Deer are easier. They just don't spook that easy. If you spook them they don't leave the country.