From what I was told by Tippmann, only a handful of these kits where released to market (no hard numbers, unfortunately) because of the difficult installation. The inside of the frame must be filed or milled to fit the ram at exactly the correct angle for it to properly trip the sear. IIRC original MSRP was between $300-$400 as well, which didn't help to generate a lot of demand.
Basically, theres a circuit board that controls the rate of fire (with something like 10-12 fire modes), an external LPR attached to the ASA provides the low pressure needed for the ram to operate, and when given the signal from the board, the ram fires quickly, trips the sear, and fires a paintball.
Here is a picture of the un-installed kit (I actually think I may have purchased it in a thread you started...) :
Oh, and... BUMP!