Anyways, back in teh real world, long extended clmbs teach you alot about the affect of climbing on average speed.

What I learned: On any route where the miles of climbing is equal to the miles descending, your average speed will always be less than twice your average climbing speed.

Bottom line: As noted by others above, going up takes away more from you average speed than going down gives you back, and that to go faster (on average), climb harder.

Physics be damned.