I received my 3 stage buffer a few days ago. I did not run any comparisons between stock and Taccom as I bought the thing, I will use it. I shot both factory and 130 pf loads thru the gun, Bill Drill-ish, and it functioned reliably with many different loads.
Comparing the AR9 to the CZScorpion SBR in the same tests, the AR9 is a clear winner for the sports game, slightly less in the cool factor.