The ATR is the best sport quad tire I’ve ever used. Super strong, takes big beatings and run 6psi. I run dirt, hard pack, some mud, rock and the tires are so freeking stable and predictable. Good traction across a variety of terrain. One rider told me they are not good in snow but since I don’t ride snow I have no idea. The XXC is the best handling ATV I’ve ever owned, incredibly nimble, fast, comfortable and if your an aggressive rider you can really appreciate the total package. Only ridden with an XMR 1000 once and it fell to the back of the pack on twisty and rocky terrain where I didn’t see it do well, in the mud it was king for sure. I would agree that you try as is first then see how it goes, I can’t see anyone being disappointed with a XXC 1000.
Make sure to grease the chassis often including the driveshaft. Amsoil Severe Gear quiets down the front and rear differentials when your ready for a lube change something to consider.