Since the Savage/Stevens guns are so easy to re-barrel in a vice they are the perfect gun to use if someone wanted a different caliber like the 6.8. I shoot a Savage and I love it so I understand where you're coming from because I get the same itch once in a while. Every time I do though I always shake myself out of it by realising that a Savage/Stevens in 7mm-08 hand-loaded would do everything just as well and do other things much better. And then there's all that money that I would save. Great light for caliber bullets in 7mm are the Hornady 120 HP for defence and varmints, the 120 Ballistic Tip for soft skinned game and the 120 TSX for heavy game. It won't recoil much with these and you can even download them if desired.
I'd say the 6.8 is close in trajectory and performance to the 250 Savage and the 257 Roberts.
I'm not trying to talk you out of it it's your gun. But I'd rather have the factory 7mm-08 myself.