RMR is the go to optic for DUTY use. The viewing window and other characteristics don't make it an ideal competition RDS.
Up until last year, I would say most people went with the Leupold DPP. It seems that the newer Trijicon SRO is taking over now. If it were me - I would wait a couple weeks. SHOT show is just around the corner, and there are sure to be new entries to the market.
EDIT - BTW - all dots will break with use. I haven't shot my CO gun much, but once you get the round count, they will break. Make sure the dot has a good warranty.
I'm running a Vortex Venom, because all of my rimfire guns have the same dot, so its an easy transition.