I have two Glocks with Trijicon RMRs. I actually am waiting for the RM06 to come up on a "good sale" again, then I'll have three.
I don't own the other two. I have shot with the Vortex Venom. If price isn't a factor, I'd definitely go with the RMR. From most of the online "gun guys", seems like RMR is the industry standard in terms of durability, being tried and true, and more.
I've read great things about the Trijicon SRO (slightly pricier than the RMR) and the Holosun 507s. Not on your list, but I've actually been wanting to try both. Sagedynamics is one Youtube channel you should look up for handgun RDS, as well as Warrior Project (or something like that), which is some asian dude with a Russian/Czech/genershizzich type last name. Those also share the same footprint as the RMR, so that compatibility is a benefit for me.
Another thing to consider is holster options. In my experience with RDS handguns as well as a bunch of my shooting buddies, holster choices can range from limited to "needing a lot of dremel" to fit since there is so much variety with RDS. I can personally attest to the "needing a lot of dremel" with a couple of my Safariland holsters.