I’ve been using the Trijicon RMR Type 2, and it’s been seriously dependable. I've really put it through its paces from range days to classes, and even some soggy outings, it’s never lost zero or had a flicker. It’s got the toughness I was looking for in a carry setup. But I’ve also had my hands on a Holosun 507C X2 for another build, and it’s awesome too. If you’re into the multi-reticle system and want great value for your money, it’s definitely worth considering!