Shorty AR Piston Uppers

[abomb60]

Thinking of turning my AR-15 SBR into a piston gun. I've been looking at options and there are quite a few piston kits and complete uppers available and they seem to be all over the place (short-stroke, long-stroke, etc). Anyone here have any experience with piston uppers in 7" or 10.5"? Currently i'm leaning towards a POF 7" upper but i'm not 100% sold on it yet.

 

[LR308_GNR]

I have a PWS Diablo... 7" barrel, 5.56 piston driven.

Not a single problem, eats everything I've ever fed it.