I finally got my SF Millenium light in (M962SU06). Since I won't have the cash for the KAC M5 RAS for awhile, I decided to get a GGG UFIR accessory rail. The 1st and 3rd holes didn't center perfectly, but it still went on without any problems. Should have gone wiht the AAC accessory rail, but I didn't want a 6" rail; I liked the GGG rail better cuz it's only 4 1/4 " in length. But, still, this is something to keep in mind if you are really picky (The GGG holes not lining up).
I talked to a GGG rep about it and he stated that he was doing to address this at their sales management meeting. He also state that the reason the 1st and 3rd holes don't center perfectly is because the rail is a compromise. It was made to fit the M4-type HG's and the standard full-length HG's. The AAC rail, on the other hand, made a rail specifically for the full-lenght HG's, I think, so that's why there's no problem, plus it only $24.95 compared to the GGG rail at $49. At any rate, the rail went on without any major problems and my DISSIPATOR looks great witht he light.
I'm gonna take it out and see how much of a problem it is not usint a rail system. Indoors, of course, the light looks like it's spot on, but who knows how it will be at EXTENDED ranges like NEW-ARGUY said. We'll see what happens...late.