I was out at the range a few days ago and got to shoot a side-by-side comparison of a piston versus gas blowback AR in .223. What a difference!
The piston version was a joy to shoot as there was no hot powder being ejected to burn me. That's the one thing I've always hated about some rifles, such as my Marlin 22. This M&P piston AR was fun and no powder burns.
OTH..the typical gas system was such a literal pain that I gave up after less than a mag. and went back to the piston AR. So, if you are considering an AR, I'd suggest trying one of the piston types.
