My experience was pretty much the same as you have written.
I'm 10mos w/ my g17 from OST.
I truly could not be happier w/ it.
My LGS owner got a g19 RMR setup.
He recently attended Costa's pistol/carbine class and really, really worked that optic over. It was scratched, scraped, dinged and dented. No heartaches, stayed on and zero'd.
The RMR made all the difference in the world w malf clrnc times and reloads w one hand, he said.
If one is willing to train to the platform, I say its a really worth-while system.