Matt I’m not picking on you but I feel some of the statements you have made represent a very common misunderstanding of the AR15 world. So, I have to disagree a bit. Colt Special, maybe not. Different, yes sir there is a difference.
How about some documentation or maybe just some other opinions. The others viewing this thread can make their own mind up even if we agree to disagree.
1) The Colt 6920 has all the most desirable milspec features. Most other brands are missing some but that may or may not be an issue to a prospective owner. Check out this comparison chart for current M4 config ARs. There are links at the bottom specs, comparison, explanations of the features, etc.
http://spreadsheets.google.com/ccc?key=pwswheghNQsEuEhjFwPrgTA
2) The mil spec is much more than machining tolerances. It is impossible to buy a current milspec AR15/M16 for private ownership. The milspec details the full auto parts. So anyone one claiming to sell you a mil-spec receiver is omitting something. We know it is not going to have the auto sear pin hole, that is a given. So mil-spec for them is advertising. I’ve seen magazine wells that were not machined correctly and would not allow a magazine to drop. The inside dimensions were not within the spec. I’ve heard of several issues with the hardness of the anodizing process. With the mass hysteria going on over the new political leaders, the manufacturers were working in an overload mode to keep up with demand. There is a very high potential for problem is the manufacture cuts quality control.
I’ve got the Mil-Spec document at the house. I’ll see if I can find it online.
3) It depends on what colts you are talking about. Some Colts have parts that will interchange. The 6920 for instance has a standard size front push pin. The trigger and hammer pins are also standard size. I’m 99% sure all current LE6xxx series are the same way.
I’m not saying the Colt is the best bet for everyone, but cheapest may not always be the best deal. At least know what you are buying and make an informed purchase/investment.