I have quite a few chucks in the shop including Bison and Gator although most of them are of the forged steel variety. I have three Gator chucks, 12.5” forged set-true that is an excellent chuck. A 6” six-jaw forged set-true that is also an excellent chuck but the backplate which is also steel was oversized – meaning slightly loose on the spindle taper. I had to regrind the backplate. Not a big deal but it was a little extra work.
I also had a 6” three-jaw direct mount cast iron chuck that had loose jaws from a very sloppy fit. It had side-to-side movement. I returned this chuck. A friend has a 6” set-true cast iron chuck which is an older Buck chuck copy – meaning single pinion and six face screws. This version was also an excellent chuck - but I don’t think they make it anymore.
So, my experience with Gator is a little mixed. The forged steel Gator chucks seem to be better than the cast iron versions, but then they’re more money. In general, I think the better chucks these days come from Europe (e.g. Bison, Toolmex, TOS, the English Pratt & Bernard, Rohm).