I looked to see if you added any information. That's a tough one to call, to me the dirt bike would be first off my list. You stated you are going in between trees and over rocks going up a hill? That's going to be a very short wheel base sxs to do that, it can be done depending on your terrain.
ATV, going up and down a hill, you're going to need ballast - front going up, rear coming down. Then, if you have a good animal on the back after a kill, the ballast will be different again. However, a good 4x4 atv with power steering will be very maneuverable.
SXS will mitigate all the cons with the ATV, but may not get between trees.
Me, I prefer a sxs, gets where I want to go, does it with more comfort and less chance of problems with hills or my worse terrains for me.