The 19X may well be my next purchase, and it may get the nod for an RMR at some point.

Hard to go wrong on that. I've been using one for most of the 2018 competition season and I haven't found much to complain about. I am annoyed by the mag compatibility issues, but that's because I have a bunch of other G5 mags. Parker Mountain Machine milled mine FWIW. I'm not much for fashion over function but with an FDE RMR it looks pretty neat.