I have owned 4 AR-15s through the last ten years. A Colt HBarII, a Wilson Combat, and 2 RRA.
For everything you will read about how Colts suck and/or they are the greatest thing ever etc... I still have mine. Two of my friends shoot Colts. I think RRA has a better factory trigger but Colt has better fit and finish...
I sold the Wilson Combat for a number of reasons. It shot well but I found that all the tacticool features it had were basically useless. I sold one of the RRA rifles to fund a 22-250 build.
As for the reliability of the direct gas system; I normally shoot 200 to 500 rounds of PMC through the course of a day in my RRA mid length without trouble of any kind. My Colt has seen over 10,000 rounds having only broken one extractor and having the trigger assembly replaced with an aftermarket one a few years back.
Depending on preference of barrel length, I would recommend http://www.rockriverarms.com/index.c...ategory_id=219