I picked up a Colt SP-1 in 1991 with all the goodies...4x scope, bayonet, bipod, and 29 magazines... Never could get the thing to group right for me and sold it...
I bought another Colt, H-Bar Match in 2005,,, Shot the 2006 DPMS 3-gun in the Tactical Iron class and didn't do near as well against some of the competitors as I had the previous year using Tactical Optics (my eyesight?, maybe) using my DPMS 16"...Sold the Colt...
I can't say Colts are measurably better, or worse, than any other AR on the market...I just don't elevate their stature above any others either...based on my personal experience with them..
My DPMS has proven reliable and accurate, above most others, and now I have an Armalite upper that I'm wringing out with a CMMG lower that is showing a lot of promise...