I have a C-More railway sight on my number one CMMG M4 clone (number one as in first aquired chronologically). Mine is a flat top though, I have an Arms #40 BUIS mounted behind it. I have some astigmatism, so I traded away the EoTech that preceded it.
C-More sights have won a fair number of matches on handguns. Downsides on an AR is that battery life isn't nearly as long as an Aimpoint (which you can literally leave on for years). Another potential problem - unless they've changed them - is that there is the risk of light reflected off it on the front giving away your position (you don't say what you're going to do with your AR and this might be relevant whether it is a hunting or tactical gun). I personally checked mine to see if it was waterproof, since I wanted to know. Thus I ran it under the shower for about 20 minutes. Still works fine.
They're noticably cheaper than an Aimpoint, even a lower end one. Far cheaper than something like a magnified EoTech with a Docter red dot piggy backed (which is a great piece of gear, but horribly expensive).
I haven't tried mine yet with my PVS14, so I don't know if the lowest brightness setting works with NVGs the way that Aimpoints and some EoTechs will. Of course if you aren't running NVGs, don't worry about that.
A C-More is also not going to be as durable as an ACOG or Aimpoint, which are almost quite literally bomb proof (ones have survived IED explosions that have ruined the rifles that they were one).
I don't know if they make one that already comes with a carry handle adapter or not. If not, you can buy one. Seems like that might put it up a bit high though.
Mine is made out of metal. I think that they may also make them out of plastic now. I'd stick to a metal one if at all possible.
With a carry handle mount that I have, it still allows one to use the iron sights. I got it free with an older Aimpoint and had that on the carry handle of my SP1 before I traded it away. I wasn't fully satisifed with having a red dot up that high. Thus my SP2 (which I retained) has straight iron sights (A1 type since I have a transitional type).
Personally, if I'm going to mess around with putting a sight on top of a carry handle, I prefer magnification. I can't afford an ACOG right now though.
My other M4 clone (a CMMG/Colt hybrid) has an older Aimpoint Comp M on it (aka M68 optical sight of earlier type). I somewhat prefer it to the C-More and it was actually cheaper since I got a deal on it by buying it used.
For all that, if you just want a red dot for a home defense rifle, I'd take a C-More over any of the Chicom copies/knockoffs, and over the dubious Sig Holosight that my 556 came with.