I'm pretty new to site too but I know a little about the Aimpoint CompML models.
I have a CompML2 which is the predecessor to the ML3. I'm very happy with it and have had it for almost 9 years now with no issues.
My ML2 has 10,000 hour battery life and I've only put 2 batteries in it over the years. Note that mine gets used very rarely as it's on my HD rifle that sits in the safe most of the time with the site set on the lowest setting.
The ML3 has 50,000 hour battery life so it's a turn it on and forget it type site. Just change the battery out every year or so and that's it.
The ML series are not considered NV compatible due to the lowest setting being too bright for NV. To the naked eye the lowest setting is barely visible though.
The site have a very wide range of adjustment so it can't get very bright for daytime use in any light conditions.
The CompM3 is the "milspec" version that has even longer battery life and is considered NV compatible. Otherwise, they are the same site from a build perspective.
These are the premier red dot sites on the market and worth the money.
I believe the site has some rules about linking to another competitor's site so a moderator might edit your post.
That being said the site is available on SWFA for a little more money and you know they will take care of you if you have any issues.
I have mine in a ARMS quick detach mount and frankly do not recommend it. It works fine but eventually the locking tab on the lever is going to bend and cause the mount to not lock up properly. I would use a different mount that the ARMS one.
In a nutshell, great site that is tough as nails with outstanding battery life.