Okay, just ordered a Rock and am looking for the following;

1 Auto brightness adjust by available light would be sweet

2 utilize the factory shield machining footprint on the gun

3 rugged and low maintenance as far as battery goes.

Basically I don't want to fool with anything on this red dot after I install it. I want it to be good for a long long time of not fucking with it.

Thanks.

A Holosun 407 K or 507 K fit on the slide without adapters.  They don't have auto brightness but do have shake to wake. The mounting screws need to be M4 x .7 x 8 mm long so as to not bottom out.  10 mm will leave the sight loose on the slide.

I agree with the above and raise you a Holosun EPS. I'm not sure that the 2 moa green currently available has auto adjust, but I recommend you try auto adjust if you haven't tried it before. I strongly prefer manual adjust. I have a multi-reticle EPS carry on order and I am looking forward to its arrival. My 507k fits my rock just fine and I used the screws from my CR920 which work perfectly torqued to spec.

If it's going to be a fighting gun, manual adjust.
Auto adjust is fine if all you do is take it outside to a range and plink.  Probably.
We're issued auto adjust at work, I went and bought my own manual adjust rmr and gave the city back their junk rmr.

I put a 407CO X2 on my Dagger with the RMR cut. The 407C is basically the same with a different dot, the 507C is the same but it has the larger circle to help center the dot. They have auto sense but you can lock it manually if you want. I tried it locked but ended up liking it more in auto. It works well. It has shake awake and they have the solar grid. Nice, if there is enough light, it runs on solar, not enough light it runs on battery. The battery comes out the side so once it's mounted on the slide there is no reason to remove it.

407/507K for me
Auto adjust is a gimmick and will hinder you in certain lighting conditions.

I’m going to get the Holosun EPS with the multi reticle. I have a 507k on my g43x and I like it a lot but the enclosed emitter is definitely an improvement on a already great dot.Holosun EPS