I own about half a dozen larue optic mounts, a few of their rails and a couple of miscellaneous products so I'll put in my piece.
Larue mounts are made to fit ALL 1913 or similar rails. Pretty much anything that's somewhat close will work. Reason being that Larue mounts are adjustable and will conform to any rail not wildly (and wildly I mean maybe with a gaping hole or a big dent wildly) out of spec. That fact alone makes Larue superior to any other QD option. Though I do own one ARMS mount (the #17S) and it works beautifully on my MRP, I have no doubt it will not be as perfect on another rail system that was even remotely out of spec. Of course the term "in-spec" means alot of things to alot of different people and you will get 10 "in-spec" items that will pass all inspections not being the same, it's a standard and therefore has variance.
Larue is the best solution to variance.