I have a P01 that I got milled fa few years ago for a Burris Fastfire 2. I am getting it re-milled for an udated optic with cowitness iron sights. I am limited in my choices The Holosun 507c or an RMR. I have been looking at the 507c and Swampfox Justice. I would greatly appreciate any opinions or experiences on which one you guys would choose. Any input will be much appreciated.