The question that's been debated since Australopithecus put two wheel shaped rocks together and called it the cyclocross bike. He (she,it) did the first officially recorded rolling dismount to get up a curb for a beer stop at the first officially recorded 7-11 store. Did Austie put it's right foot through or behind? No records exist of the exact method, but the entire fate of the planet has been hanging in the balance since.

To help resolve our ancestor's methods, what's the advantages and disadvantages of each? I've got a definite preference, but I won't weigh in yet, due to political reasons. And besides, I know only a gram more about CX than natural history.