it matters on the floor material too... just as in 'race' cases. you want tread to let the rubber get to the ground without hydroplaning if you have wet or very dusty ground.. but in very well conditioned tracks, (such as very smooth asphalt with sugar water sprinkled on) you want the slicks... as in our robots, too.. if its a very smooth plastic floor, no tread might give you more traction.. and then theres a matter of do you want that much traction? as in 4 wheel drive skid steering.. do you want to stick to that floor that much?
and then again, what material tires are you using? if its a soft gummy rubber, its definitly going to be different from say, abs tires..(works very well for drifting
)