Agreed, the RMR wouldn't be as popular as it is if the bottom mounted battery was that big of a deal. The advantage of the lower body profile goes along with that bottom mounted battery too.
Blue, FYI, you'll want to Loctite that DPP rear sight in place really well. They do tend to come loose otherwise.
I've installed one Vortex optic on a Glock slide, and tried to talk my buddy out of it in favor of a better optic. I wouldn't consider mounting one on any of my own pistols unless it was just a range toy, but even then I'd just spend a little more for a DPP.
