I have one of the Glock MOS's. also have a Glock with an aftermarket slide cut specifically for the Trij RMR. the MOS, being universal, mounts the RMR higher than the RMR-specific slide since it has to have an adapter plate. Since I only consider the Trij RMR, I shoulda gone with the non-MOS and had the slide cut specifically for the RMR. makes for a lower combo. in retrospect...
some of the prices on the Glock RMR-cut slides nowadays are really attractive, e.g. Brownells, Lone Wolf.
when Trijicon vendors were trying to clear out the original-style RMR-06 inventory to make way for the Type II RMR-06, there were some one-time terrific deals to be had. combined with a BattleWerx plate, not so sure if there's any appreciable difference. but, just MHO.