I called Colt today (800-962-COLT) to confirm a S/N as preban. After a lot of the negative stuff I've read here, I was very pleasantly surprised. The total wait on hold was 6 minutes. The advertising on hold also included a very strong encouragement to join NRA.
When I spoke to "Cindy", she had the answer (July 1994) for me in less than a minute and apologized for not having it quicker! She also offered the written confirmation for $25.00. I don't know if this is something new, but the last time someone here mentioned a price I think it was $50.00.
I obviously don't know if this has carried over to repair and other services, but this was, all and all, a very positive experience.