I actually worked the launch in a sense. I worked the toy department in Meijers, which included games. It was a 24 HR store, and I was working at midnight when it turned 9.9.99. Launches then weren't like today. There was no crazy line, but we did sell a handful of systems, controllers, VMUs and games. Sonic Adventure sold well, but so did NFL 2k and Powerstone, which somewhat surprised me.
PlayStation, however, was still king, and there was more excitement for the upcoming PS2.
The Sega fan in me wanted the DC to do better. I wish Sega hadn't burned so many bridges with the Saturn (I liked the system, but retailers weren't prepared for the surprise launch, and 3rd party relationship got strained). I also think it was a mistake not to use DVD technology. DVD players were expensive and the PS2s ability to play DVDs was extremely attractive to potential buyers. If the DC could play DVDs, it may have given it a better chance to survive longer than it did.