[Anupam Goli]

Treaded wheels usually get you a better COF on carpet, where you can actually dig into the material*. Solid rubber/urethane wheels are great for flat, hard surfaces and usually great for intaking/manipulating game pieces, from my experience. So I guess it's ok to say we use both wheels, just for different purposes.

*in the case of a game like 2012, where half of the field is plastic, going with wheels with a good COF on carpet and hard surfaces (Colsons cut to mimic a tread) is a safe bet.