Cheap chicom imports like the sig, burris, holosun mentioned have no place on a defensive weapon or anything you need to trust your life to.
Sig does make some red dots in the US, but they are comparable in price to the quality domestic ones like RMR and Leopold Deltapoint (Romeo 1 pro, and while the deltapoint is made well, its not durable enough for a duty/work/SD gun)
Despite what some paid for shill youtuber tells you, Stick to the big 3.
Aimpoint, Eotech and Trijicon.
Is your life not worth a $300 proven piece of equipment?
Eotech makes the fastest optic in the world, however there are drawbacks such as having to turn it on and much shorter battery life. For a tier 1 assualter it makes sense to get that small edge, but it comes with higher maintance and there is always prep time before hitting the target. Getting woke up in the middle of the night is not the time to try to find the on switch to an optic.
Trijicon makes a nice little sight in the MRO, however it has delicate battery terminals, has parallax shift, is slightly magnified giving fish eye and has a terrible blue tint like their RMRs. They also have considerably lower battery life than aimpoint. On the 2nd to highest setting I was getting 4-6 months before battery needed replacement. Not that big of a deal but more than once I picked up the gun and realized i had a dead battery.
Aimpoint have crystal clear glass, are bombproof and have amazing battery life. I have gone to Eotech and Trijicon more than once and always end up selling them all and buying a shit load of aimpoints. I think I am up to 8 or 9 various ones now. Not going to make that mistake again. Aimpoints also have the ability to carry an extra battery on them, which is nice if you are out or don't have a spare in your bag (Which you should have).
A typical 4 MOA dot will allow you to make reliable COM hits out to about 300 yards. The newer 2 moa dots allow more precision shots, but with bloom and its really not that much of a difference.
A 50 yard zero will give you good point blank offset and your 50 and 200 yard shots will be dead on with a typical .223/5.56 load.
Now if you have an astigmitism like many of us do, all red dots will look like oblong blobs. You can do a Prism sight but outside of the Steiner, most are more cheap chicom junk. An Acog like the TA33 may also be a good option but will be slower for up closer and you have issues with reticle illumination depending on your environment. Or just suck it up and rock a red dot. That would be my advice.
Hard to beat an Aimpoint Pro. $425ish new, $3-350ish used. Comes with a serviceable mount and a 5 year battery life that on max setting is more like one year. Never turn it off and change the battery once a year. No cheap chicom electronics to fail or a drifting zero.
Now if money is no issue, Look hard at the newer LPVO. With true 1x like reticles, there is no such thing as too much optic for a 10.5 or 11.5" gun. The NX8 would be perfect for a small carbine/pistol but the reticle sucks for longer work and the eyebox is kinda small. It does have a nuclear bright dot which is a must have for a fighting LPVO. For close in oh shit shooting you want a forgiving eyebox for heads up shooting. Money no object the Best to least Best would be the S&B CC Dual > Vortex Gen 3 > ATACR 8 > Gen 2 Razor > Kahles 1-6/8 > Eotech 1-6.
You could do the dot + magnifier but after running them for a few years, I went back to LPVO. Just a much better solution in a smaller footprint and way more versatile.
Lots of choices but choose wisely.