So I finished my CMMG lower the other day and I ordered my upper from CMMG earlier today. So now I'm in the market for a BUIS and am looking for recommendations. It needs to be a flip up/down, since I want to run optics down the road. So far the ones I've heard of and looked at are Troy, MI, A.R.M.S and YHM. Looking for opinions on the best bang for your buck BUIS. Thanks!