Violator22,
Actually the ATR uses a nut the same as the Stevens/Savage, it's just tapered and harder to see. You could swap barrels as easily. Also, the interchangable bolt heads of the Savage/Stevens is great in theory, but try to find them. I have been trying without any success. I was talking to Mysticplayer on this and he is having the same issue.
I am not saying the ATR is better than the Stevens, but the features are the same if you wanted to do a swap barrel thing. I would add a few bucks and get an SPS myself, but the ATR and Stevens 200s are not bad rifle values for the money.
I just got a Remington 710 to try out. Now there is a real piece of stinky!