I found out something from a gentleman that works for Colt, Cory Francis. Colt uses the same process and parts and such for manufacturing and inspecting their in house commercial rifles as they do for military rifles. The barrels are different lengths (but adhere to the TDP except length). The lowers are the same forging, just milled differently (with the sear web) and of course have the sear. All of the parts are as close to the TDP as possible (most are the same parts).
Colt however sued FN and won the rights to the TDP. Meaning FN can use it for their military rifles but have to change their civilian rifles. I believe FN has better barrels with their chrome lining and such. But that is a matter of personal opinion.
That being said, if a Colt were the $899 I paid and a BCM was $1200, I personally would pick the Colt. I love DD but they cost even more than than BCM. Colt was honestly the best milspec bang for the buck. There are many companies that meet and exceed milspec in many ways, but there is also a reason that the TDP is still used today.
I am not defending Colt, but from a business standpoint it makes sense. They make far less off of their AR line then they do the new Colt Cobra, King Cobra, King Cobra Target, etc. The Python, and Anaconda are coming back too. When you have most that would just soon buy a PSA or S&W Sport for $300 less. Most never run the volume or rate of ammo through an AR that USUALLY makes the Colt, FN, BCM, DD, and LMT rifles marginally better. Does that mean that Colts are more dependable, no, does it mean it is worth more, no. I have had a Del-ton that I trusted more than any because of the amount of rounds I put through it reliably. Colt isn’t the company it once was. But they usually do run, and run. The majority of the people who work at Colt punch a clock and don’t care if they make ARs, pistols, or widgets.