I have a SWS E1 on my AR-10 and highly recommend it. The photos of the product don't do it justice. I have 3 Larue rails for my AR-15's, and have previously owned KAC and (back in the day) an ARMS SIR, and the SWS is first rate. My only complaint is that they don't offer a slightly longer version that would cover the gas block on a rifle length barrel and still have the full rails. They make Noveskes rail in a 14" length, but its not offered as a stand alone part. Another thing to consider with the SWS is the price includes the barrel nut wrench in the price, unlike many of the others...