We disassembled our 1998 and 1999 robots at the end of the 2001 season, when we had to pack up all our stuff and move out of our shop for a year. They were non-functional, and just taking up space that we didn't really have available. It would have been nice to keep them for old time's sake, but we really had nowhere to put them. Amusingly, we saved all the parts, and ended up using quite a few of them on our 2002 OCCRA robot, and a couple on our 2003 FIRST robot.
All our robots from 2000 and later are in storage in our shop. We still pull them out for demos and testing a couple times a year. It's a really nice thing to have 5 functional and very different robots available for testing. And, we've found that some of our older robots make better demo machines than others. I think our 2002 'bot has done more demos than any other robot in our team's history. It's small, sleek, and just looks cool
Plus, it doesn't have the tendency to attempt to kill people like our 2001 'bot... not that that's ever happened or anything...