[EricH]

Originally Posted by P. Fuller

Also, if there are bumps in the field again (like 2010), casters are much more likely to break than a slick wheel from 2009 (which has the same effect as an unpowered omni). Overall, slick wheels are an easier and much more reliable solution.

The 2009 slick wheels, though, have a much higher CoF in the sideways direction than an omni wheel (which is near zero, due to the sideways rollers). So, they will drag, which makes turning that much harder. While it won't be as bad as a 4WD all-traction setup (which could be really bouncy, depending on traction), it still won't quite perform as well as an omni wheel, powered or not.