[Donut]

I'll just play devil's advocate here and note that we were an alliance captain and regional Finalist the only year we ever used casters on our robot.

We did hate them though, enough that we tried replacing them with skids at Championships that year (which may be the only thing on earth worse than casters, we only won 1 match at Champs as a result of them). I'd recommend switching to omnis as others have said, they're easy to use and became 498's go to drive train starting in 2007. There are some situations when they provide an advantage over the 6 wheel drop method, namely when rocking is unacceptable to your design or you want your robot to turn about one of its ends rather than its center.