Two of the outstanding qualities of AR's are Accuracy and Parts interchangability. Piston AR's reduce both while increasing cost.
I've had both and now in AR-15's I only have DI's. For a first AR-15 I think the recommendation for a Colt 6920 or 6940 is solid advice. Later on for target models etc. you'll start building your own............dj
Remember this is all supposed to be for fun.......................
