[mrnoble]

We have used the basic AM 6" wheels, the HD wheels, and the vexpro wheels (all 6"). The HD are by far the best quality if you want durability and reliability over a long term. We have used them for our 2015 competition not, and for a "chairbot" which is a big hit as a promotional tool. We've probably put more than 100 hours of solid drive time on the HDs with no failures.