From doing a search on B100Rs, I've found that most people agree that since ampegs moved their manufacturing to the Yelville (sp?) plant, the quality has "improved greatly." I'm currently shopping for a B100R, and I'd like to know: 1. Is there much of a difference between these amps that were made at the "old" factory and those that are currently being made at the "new" factory? It's located in Arkansas, if I'm not mistaken. 2. How can one tell where a B100R has been made? I believe the serial number would most likely give this away. Thanks!