Everyone has different experiences and not every work order is for a misbehaving pistol. I understand the frustration but selling one off on principle is an emotional response to a disappointing experience with, I suspect, a less than critical evaluation from Colt. What if the extractor tension on the EMP loosens over time or the magazine springs weaken and the pistol jams?
A simple email to Brent in the Custom Shop would have gotten you a reliable pistol and a far different outlook on Colt. I try to approach things systematically with a plan for what I need, who can best help me achieve my goals and how to get them involved. I want the gun to run, Colt's repair department couldn't help, I call the Custom Shop, ask for Brent and introduce myself as a longtime shooter of 1911s and (insert qualifications ie. LEO/mil./IPSC competitor) who would like his Colt XXX to work. I explain inspector 7 may have mis-diagnosed shooter error as my Kimber, S&W, RRA and Detonics all toss brass fine, I ask for an intervention, I thank him for his time.
A simple letter included with a return will often net similar results if you include information regarding skill level (owner of 20 1911s from Govt. to Officer) for 25 years, shooting 230 gr. Federal ball ammo, experienced problem from 6 magazines (Metalform, Colt, Wilson), no pattern to the problem, happened X times in X number of rounds fired, brass severely dented- see enclosed photos denoting brass damage at 12 o'clock position.
Standard protocol will not be to test fire 100 rounds to check function so being specific tells a trained tech that you've done your homework and let's him know that you're not a first timer who was shooting at flying geese when the problem occurred. I don't suggest everyone sending problems straight to Brent but when other avenues close it can be a useful option.