I had the chance to handle one, and it's a decent product for a Colt rifle...if you think you need one.
The biggest limitation that I saw was with the mag-well adapter in place, the standard AR-15 upper can not be opened more than about 3 inches from the back pin.
Just enough to to get the BCG out, and that's it.
The adapter also really limits the free-float tube options, as the pins and the block require a bit of forward clearance, and only a few AR-15 tubes will work. We tried a couple of Ar-15 uppers with standard (Troy, YHM) float tubes, none worked with what we had.
The circled area requires clearance to pin the AR-15 upper on, the square area needs to be clear so that upper lug can reach the pin.
This is a bit better view of the AR-15 upper pinned on, the angle of opening, and the clearance needed to pin the upper onto the adapater.
I don't know if the owner has fired the rifle, was supposed to a couple weeks ago, but haven't seen him to ask.
Unlike most Colts I've owned/handled/shot, this one did not have much play in the upper and lower, a nice change from my experience with Colt ARs. Seemed to point well, a bit heavy as a .308 rifle, but not horrible. Definately a bit heavier with the AR-15 upper than most, but more material in the lower, to be expected.
The price point would have to change a bit before I grabbed one, but the demand seems to be there for now. They are not stayed in the LGS, and sell regularly from what I've seen.