[EricH]

The McMaster ones are high-traction. Give us 2 of those as our center wheels, and we'll able to hold our own in a pushing match if needed. 4, and we'rr a bit better. They wear well, too; when you see the red, pull out the spares, but you've got a few more matches. One set could last an entire event, eliminations included, and be usable in practice later. The cost is about the same, $20 US/wheel, but McMaster is known for fast shipping if they're near your area (and willing to deal with you).

I don't know about the MBS wheels in terms of traction and wear; mountainboards aren't exactly designed for light use, though. (And they're not designed to be self-powered...)

Looking at the Radio Flyer wheels, they're more expensive (over $25/wheel) than either of the other two. Again, no real experience there.

The biggest problem with all of them is that they will need modification to work with a drive system. A sprocket needs to be attached somehow. See the explanations earlier in the thread.

If it's track record you want, McMaster wheels have a lot of regional and Championship wins, and I don't know of a single failure other than tread wear, which everybody has. I don't know about the other types mentioned.