can anyone tell me if there is a BUIS called UTG...reason i'm asking is... i bought my brothers M&P 15OR and the BUIS seem of poor quality...there is a large wheel under the rear sight for elevation...about the size of a quarter($.25 cent piece)...the front sight is on the gas block (i believe it is called)...appears to be made of aluminum alloy ...i'm thinking the Troy Battle Sights would be of better quality...am i on the right track with my thinking? can i even use the Troy Battle Sights?