I do not have a Colt, but I do have a couple of nice ARs, as well as a Sig 556 Classic. Both platforms are excellent. The Sig has slightly less felt recoil, is a little more barrel heavy, unless you have a heavy barrel AR, and has the versatility of the folding stock. It is very easy to shoot well folded or not. The detachable rear sight on mine works well, but is not as tough as say a Troy Battle sight for the AR.
If I had to give one up, it would be a tough choice. Thankfully, I don't have to.