I think the pro/con list above is pretty accurate. On the weight/efficiency side though, the reflex cans keep more of the weight farther back so it, in effect, will feel like a lighter can.
I have one of the AE M2 cans, and also had Ron make up an AE M1 (same as the old OPS M4S). The M2 is a good compromise, I wanted the smaller can to make it a little easier to get in & out of the vehicle racks. Both are on dedicated guns, so removing/swapping isn't an issue. I went with the AE cans because I wanted something that would be as compact as possible.
The build quality of both appears to be very good. The machining and everything I could see of the internal assembly is very clean and precise. My dealer even commented that the build quality is better than some of the other cans he's seen, and on-par with any of the top manufacturers.
The M2 is comfortable to shoot outdoors without ear pro, the M1 is not comfortable, but it does still make the rifle substantially quieter. My ears won't be bleeding if I have to shoot inside without ear pro. The M2 is on a 10.5" gun and the M1 is on an 11.5" gun. You can get the standard mounts to work on a 10.5" gun if you're not shy about cutting down the length of the gas block to be about flush with the front end of the gas tube.
The mounting really isn't an issue for me, since they're dedicated to the guns. Even with their older screw-on mount, they're not exactly slow to get on or off. IIRC Ron recommends between 6 and 8 complete turns until the can fully seats. Carbon buildup can make them tough to get off, but a cheap strap wrench (or Blowers grip strength) makes it a simple task. The real limitation of the mounting system is that you pretty much have to run a gov/M4 profile barrel with the little shoulder cut 1/2" from the start of the threads. A lightweight barrel is a non-starter. I asked Ron if there was a way to make a mount that would work and the short answer was no.
The M1 is run inside a Seekins forend with a Ti header wrap heat shield with about 1.5" sticking out the front. The handguard does get uncomfortably hot after about 60 rapid rounds (back to back 1-5 drills with a D-60 mag, for example) but I usually run gloves with the rifle and have enough stuff attached to the front of the forend that I don't have to move my hand back very far to get off the hot section. I don't know if I'll stick with this setup. I've been thinking about trying the AEs on my longer guns, and using the SF Mini that I have in ATF jail on the SBRs. For my role, the chances of being in a prolonged shooting engagement where the heat would even start to be an issue is very slim, so it's really only a training day consideration.
Another selling point of the AE cans is the price. They're relatively inexpensive, especially considering the build quality. This is probably due to the simplicity of the mounting, but that is really a non-issue for me.