I have yet to own one, i plan on odering one with my income tax this year, but ive done some research on forums and such. Apparently, lots of people had serious problems with the Polymer versions, but anyone who owned one in an aluminum body compares the structural integrity to EOTechs. They have been used on large pistol calibers for years so rest assured they can take the hammering of high volume firing. If your talking about the C-More for an AR rifle, the ATAC aluminum body seems to be a GRAET option, its the one im looking at buying soon for my rifle. It comes with the flip up rear backup sight as part of the assembly to take full advantage of your flat top upper. Ive read lots of peoples comments, good and bad, and the bad ones seem to be from people with little or no actual experience with them. What gun are you wanting to mount it on? theres only 3 for rifles i believe, and numerous versions for pistols. From everything ive heard, you shouldnt be let down if you get one. Hope this helps.