I have an UltraDot MatchDot on my SBHBH that has seen thousands of rounds without issue.
There is also a Leupold DeltaPoint on my Redhawk that has seen a goodly number of rounds and has held up well.

As far as the micro red dots go, I like the Deltapoint due to the larger window and clearer lens than say the Trijicon. That said my 500JRH wears a Holosun 507C-GR (green dot) which has been reliable so far (<100 rounds). The feature set of the Holosun is going to be pretty hard to beat if the sight holds up.
- Same mounting pattern as a Trijicon RMR
- Manual (button) or automatic brightness adjustment
- Shake awake
- Multiple reticle options
- Solar + battery power
- Something like 50,000 hours battery life

I am also really liking the green reticle over the red. Even against a green background my eyes tend to pick up the green faster.