I was lucky enough to shoot one a couple weeks ago on a Glock 34.
I've always thought that slide mounted RMRs were neat, but a non reciprocating dot is way nicer. Obviously, the trade off is that you've got a gigantic mount for it, making the pistol pretty unreasonable for most things. Upon shooting one, my initial suspicions were confirmed. Neat as hell, you bet. Practical? Not really.
For your HD scenario as mentioned, I've personally never felt limited by a WML and irons, especially at hallway distances. My AR also has a SF muzzle brake on it, but I keep a set of Sordins right next to it. Atleast until the suppressor paperwork comes back.