I purchased an ATR 100 in 270 last winter and I've shot about 400 rounds out it so far. I have both a Stevens 200 and the ATR. I find the ATR more accurate. It has a nicer stock with an effective recoil pad already installed, something you may need to install after on a Stevens 200. The ATR barrel is a thicker and has a recessed crown which may account for the better accuracy. I've been so happy with mine that I would purchase another in 30-06 if I didn't already own this caliber in another make.
As for the 4x4 I have little experience. I've held one and I didn't care for the detachable mag. It felt cheap. The trigger is the same and can be creepy, I've had mine adjusted by a smith.The pros: 24" barrel in standard calibers, ATR is 22", and the same good action as the ATR. Also, although I the design of the stock is unconventional, some might say ugly, the laminate version feels pretty solid.
Good luck with your choice.