I have a Crimson Trace RAD micro red coming tomorrow hopefully. Amazon Red is $175 Green is $197. I was going to get green, but I read alot of reviews saying that it was too dim under certain cicumstances.
If you are interested in the Rad micro, look for
MrGunsnGear Channel review on youtube.
I also looked at...
1. Holosun 407K-X2 and 507K-X2 red and green, requires adapter plate or grinding and co-witness is iffy
2. Swamp Fox Sentinel - green or red, co-witness may be iffy? but but supposedly no mods required
3. Romeo Zero Elite? - I didn't find alot of info, but supposedly no mods required
4. Romeo Zero - durability issues I think, but supposedly no mods required
5. Hex Wasp Micro - don't remember why i ruled this out. price maybe? but no mods required
6. Shield Sights RMSw - I couldn't get over the price, but no mods required