I'm not saying it's not a hard target. It's a tight shot to hit at speed by any standard, quite fiendish really as it definitely prods you to go much faster than you're capable of consistently.
I'm not sure that we can't talk about at-speed shooting challenges in a vacuum though. I think to a guy that can shoot a plate rack at 25 yards in under 3.6 seconds and a Bill Drill under 1.6, a sub 5 second FAST drill isn't any special feat. Sub 4 seconds, that's getting pretty tough, sure. According to Ben Stoeger at least, 4 seconds is a really bad run for him.
I don't really think the classification of GM means anything when taken by itself though, certainly not when talking about a test like the FAST. That said I obviously have no idea who you've ran on the test and who has still failed to get coins, but I would argue that your average GM is only any good with race equipment at wide open targets inside 10 yards or so. Not running from concealment with service pistols at 3x5 cards.
Anyway, I'm really losing steam with this argument, no matter how you cut it it's still a really fun test, and a hard one for anyone to do well at. I shot it with my SIG from AIWB a couple months ago for the first time. My first run was a clean 7 or 8 or something because my slide didn't lock back. Second run was a 4.23 IIRC, -1 to the head just low. So obviously I wouldn't have gotten a coin on my first attempt either, but I also suck and aren't even a GM anyway