Colt is wasted money if you ask me. Other makers are much cheaper and they are trusted by hundreds of policemen around the US. RRA, Double Star, S&W, Bushmaster, etc. will last you just as long and shoot just as well as a Colt. Everyone acts like Colts and Noveskes never break down because they are "Mil Spec" but they are just like any AR in that they need to be taken care of to work properly.
Save the few hundred bucks for a nice quality optic or accessories.
I have 3 ARs and I have shot about 6 brands. The ones I own are an RRA midlength, a double star 6.5 grendel, and a DPMS 16" Bull Stainless. Of the three I could trust the double star to function every time right out of the box. The RRA was my first and it took me some time to learn the workings of an AR but once I found out that you had to lube them more than a regular rifle, it has worked flawlessly. After about 300 rounds it did not need near as much lube to keep it running and it is my most accurate one to date. The DPMS works flawlessly, but I couldn't get it to group well. The upper was sold and the lower is now waiting for a new partner.
All of these rifles have shot as reliably and as accurately as the 2 colts I have played with. I have also shot a del-ton and a bushmaster that worked well but seemed very loose to me.