Glynn,
I've got a Shield RMSc, no issues to date (had it about 1 1/2 years). Like it as it is like my Trijicon... always on, auto-adjusts to the light conditions, and battery life is over two years (I change them out once a year). Some folks had issues with the plastic window getting damaged from brass, they offer it in glass now. Midway sometimes has some pretty good sales on them. Like that it co-witnesses with standard irons (not suppressor height), should say that this is without an additional mounting plate under it. I feel co-witnessing is important as it is kind of like training wheels for quickly acquiring the dot.
Got the Sig Romeo Zero, the first ones had issues, haven't had any problems, but don't have enough time with them yet. They are all plastic and I don't feel like I am holding a quality piece, going to just use them on my Ruger 22 LR pistols.
The Shield RMSc and the Sig Romeo Zero are much smaller than the Trijicon. Trijicon did come out with a smaller red dot sight, but they used a unique footprint, otherwise I would of picked one up.
I keep hearing good things about the Holosuns, but have no experience with them.
You might be better off tripping your present pistols and buying the latest version, most are set up for an optic mount now.
Your present holster may need to be altered to work, or you may need a new one that will work with an optic.
Jerry
from pullit; "I took another route and bought a M&P compact already set up for a red dot. Sometimes you can catch them on sale for under $500."
I believe S&W has a $50 rebate until the end of the year.
Last edited by jerrywoodswalker; 12/12/22. Reason: added pullit's quote