I have been running one my 11.5" AR for just over a year. Compared to my buddies Battle Comp, the Jake Break is a little quieter but recoil reduction seems about the same, to me anyways. Prior to the JB I was running the PWS and the JB is a better system for me. It is a great piece for those looking for a combination flash hider/comp. Plus like Dave, it is nice to be able to slap my can on the rifle in less than 2 second and be ready to run it suppressed.
You can also check out Am-Tac, formally Ambush Tactical. They are the designers of the Jake Break. There is more info about the break on their web site, I even think there is a video or two out there involving the JB.