I'm still on the fence on which way to go as I'm afraid I won't feel a lot of difference with the 3.73. I also know if a lot of power mods are done it's better to stick with the stock gears.
Having said that, I was talking to my son's basketball coach on this very topic as he's a professional engineer that fabricates race cars for a living. He said anyone can get in a car and nail it, but it's the good driver that understands throttle control, and he recommended 4.10's all day long (especially with 5th and 6th being overdrive gears). Of course his opinion is like an *******, everyone has one.
I remember my first street-legal motorcycle was a Ninja ZX9-R (this was well over a decade ago) and it was the first production bike to break into the 9's in stock form. Many people thought I was nuts starting off on such a powerful motorcycle (and many people thought I was nuts for even having a motorcycle), but I made myself respect the throttle and everything turned out fine. No way that bike would run a 9 second 1/4 mile under half throttle. However, once the bike was underway and rolling along in 3rd or 4th it was a huge grin factor to feel it blast from 50 to 120, and that's sort of what I'm shooting for with the GT500.