What are your preferences for red dot for an AR?
I just ordered an EoTech EXPS 3-0 for an AR. My first AR had an EoTech 512, but I got rid of that dot a while ago. Nothing was wrong with it and I didn't experience the problems with the battery compartment that many others reported. I just chose to go a different way at the time.
Since the 512, all of my ARs have had Aimpoints. CompM4s, T-1s, and a PRO. All have worked flawlessly. I recently sent the CompM4s back to Aimpoint because the dot would come on when the knob was turned completely off. While the dot still worked, I didn't like that if I had the dot off when storing that it would drain the battery. Aimpoint ended up replacing it with a new one.
My preferences currently are just 1x. I haven't really tried a magnifier for that long, but I have never felt the need for one. For my shooting, the 1x is fine, but I also understand that there are other uses where the magnifier would be helpful. I've wanted to try a 1-6x or 1-8x for a while, but I could also see the magnifier being "competitive" in that group.
For weight, I like that the T-1s are super light, but the size or weight of the CompM4s or the PRO have (ETA:) never really bothered me.
What is important is durability and reliability. Aimpoints are well known for both. I've read many things about the EoTechs and I've seen them have problems in classes as well as just on the range, but I also wondered if those were knockoff. That and I've also seen Aimpoints have problems as well.
I've also been interested in trying out dots like Primary Arms and Vortex, but just haven't had the chance.