Picked this up a while ago for my M4 AEG, I wasn't aware that MagPul PTS made one at the time, but anyway here is a quick review.
I bought a clone MS2 along with this as I though they would go nicely together. The A.S.A.P clone came in clear plastic, stapled together at the top with a piece of black cardboard with the Building Fire logo. Taking it out of the pack there were no surprises so I went ahead and installed it on my AEG (which is a JG M4A1) with no problems.
Some pictures:
Overview
Pros
+ Around half the price of the PTS version (Cheap!)
+ Decent quality