It's terrible. I've seen garage-built guns better than theirs.
In fact, a guy I know built an ACTUAL water-cooled M16. Red Jacket made the worst water-cooling rig I've ever seen. The fellow I know actually built a complete water jacket like a Vickers, from the chamber to the muzzle. He likes to shoot Beta mags at MG shoots.
That is my point, the show is ridiculous. They go from a temperature of approximately 760 degrees barrel surface temperature (after dumping 3 beta mags) to like 82 degrees on the outside surface of the water cooler after firing 30 rounds. Later on the head guy says that they had a 40% reduction in temperature. I am no sciencelogist, but the methodology and basic arthriticity seem a little off to me. Supposedly they were building this for the "Navy", which is totally insane cause I am pretty sure the Navy would have access to various sorts of light machine guns to fill that exact purpose without all the modifications. Along those lines, the Navy Special Forces guy...I think he tried to sell me some beef jerky at a gun show once.
On a whole I think it is good to have "gun friendly" shows on TV, its just these guys aren't exactly the people I would pick to help spread the idea of responsible gun ownership. I know a lot of it is probably just the normal reality show TV drama, ala Jay and Top Shot Season 2, but I don't know if I would put my reputation on the line for a couple of bucks and some free publicity.