I've got three EOTechs on three AR-15/M-16 uppers. I like 'em for 200 yards and closer. Anything longer than that probably needs magnification IMHO.
I've run a pair on two different subguns but have moved to a C-More Railway on my MAX-11 due to the C-More's smaller width which doesn't interfere with side cocking upper. They're a very nice red dot for less money than the EOTech and will stand up to 5.56 rifle recoil just fine. The nice thing about the C-More is they have user replaceable diodes allowing you to change the MOA dot size for about $40.00 each. I switched from a 2 MOA dot to a 6 MOA dot on the subgun. Much nicer for close in work, but I can use the 2 MOA diode on a rifle if the mod strikes me.
Both are great optics that are absolutely BRIGHT in harsh desert sun. I've had a couple of friends who thought they could go cheap on gunshow knock off ChiCom clones. The look plenty bright inside, but once you mount them and take them into the bright sun, it's very difficult to pick up the dot. Often times they lose their zero after a couple of hundred rounds. Buy once cry once. I can't say that I've ever regretted buying quality products, but I have had buyer's remorse on cheap products.
<img src=" http://i16.photobucket.com/albums/b17/VegasSMG/Image099.jpg"
Yeah, I like EOTechs... a LOT.