I am at toss up point on that myself. I just finished a new 7.62X39 with a 16" barrel and went with a mid-length gas sort of as it was the way to go. I have a 5.56 and a .300 both with 16" barrel's and carbine length gas. I can't wait to get this new one to the range to flex it out and see if there is any difference I can tell.
I know there will be a big difference in drop off with the Rusky round at 300 yards and beyond. Plus the recoil will be a bit brisker with the Amerikansky 2 than the Rusky and that may make a difference on running a few boxes of ammo downhill, but we shall see. Looking forward to doing this soonest.