The slower cyclist will save more time over the same route from the aerodynamics. Watts at his same speed - a higher percentage perhaps if not more watts absolute. And a pound is a pound, slow rider or fast.

Either way, Drew Eckhardt has it right in this thread that rotational mass doesn't matter much. In a race, if you need six inches in a sudden charge, or need to stay inches close to wheel in front, yes. I can't say I've ever wanted that, not racing. He's also dead on that more aerodynamic wheels will improve speed, but not so much that you'd notice.

The efficiency of a standard traditional hub (inexpensive) is so high that gains from ceramic bearings and exotic materials is by definition trivial. Because of the availability of parts and ease of repair, I think I'd prefer something like a decent shimano hub to an exotic expensive one even at the same price.

I kind of agree that if the shop noted that OP's bike was anything but a high end race bike (forget about the comfort saddle type depictions, anything but top of the line racing) they'd know he would be disappointed in thousand dollar wheels. I can't fault the shop on this one.