If you're looking to splurge, go with an RMR. While I've never held an unmounted EO, I'm betting it weighs in the 1/2lb to 1lb ballpark if it's anything like my Meprolight. Too heavy and too bulky for a PDW build. Imagine trying to put on the same stunting moves after gaining 100lbs

Again, if looking to splurge, something from Aimpoint would be a distant 2nd choice, but RMR is a lot FASTER. I am running a Deltapoint on my 22lr AR build for speed. It's an option but I figured you'd wanna go with something sturdier if you're doing a tacticool "PDW" build.