First, All my experience with AR types is with the M-16 I had in NAM back in "68". Lots of different ones to choose from nowadays. I'm thinking about getting a Colt M4 or (maybe) one from Stag Arms. How do the two compare with each other? Also, 1 in 7 vs. 1 in 9 twist, any advantage in performance in one over another? Any input will be greatly appreciated. Thanks.