my $.02
what happens to your robot's legs when a 6WD comes over and rams the bolts out of you?
of course, i'm thinking of the legs being fairly long rather than thick logs that don't have much of a vertical component.
I'd love to see legged robots in FIRST, but i don't see it happening unless there is a "double" terrain, where legged robots can go, but if your robot has only wheels it might not be able to traverse that area.