Ran it a couple of days ago, shoots almost identical to the MB556 (as expected).  For the price, it is definitely hard to beat. Right now I have a mix of SFs, and battlecomps and I'll probably stick to them.  I still prefer the look of the MB556s but I think that the procomp it is a good option.  The price is better than most brakes out there and functions as good as or better than a vast majority of devices out there.

First impressions:  Looks to be the same size ports as a regular MB556.  The MB556 works fine so this should as well.  I can see where they cut back on costs, comes in a cardboard box, crush washer, and simple instructions.  Looks like they're planning to release a flash hider along with this.  3P Eliminator Flash Hider. The finish is a little rough with tool marks, and really shallow name engraving for PROCOMP and Surefire.  It is a pure basic form of the MB556, which is what I expected to get for $52 street for these.

In comparison to other brakes it is relatively the same size as the MB556's.  I threw in a Battlecomp BABC to show size relation compared to a Battlecomp 1.0.  Left to right - Spikes Dynacomp, Fortis RED, Rainier Arms XTC, Battlecomp 1.0, Surefire MB556K, Surefire Procomp, and Battlecomp BABC.  I'll be taking it out for some shooting and comparing to a regular MB556, and a Battlecomp 2.0.