Hi Rusty -
I think the comparison could go either way.
Probably the absolute least energy-intensive way to descend a smooth, well-packed slope at a constant downhill velocity is to stand almost perfectly still and fast sideslip the entire thing, staying in a narrow corridor, and making no changes in the direction your skis are pointed.
If the surface is sufficiently smooth, the only thing the skier has to do is make barely perceptable fore-aft and edging adjustments. Since his muscles are barely changing length when skiing this way, and since the only force the muscles have to overcome is only 1 G, the skier will use only slightly more metabolic energy for this sort of sideslipped descent than he would if he had simply stood absolutely still for the same length of time. By the time the skier gets to the bottom, he might be a nervous wreck because of concern about catching an edge, but at least he won't be winded.
Because this skier is doing little more work than he would if standing still, this endless sideslipping technique will almost certainly use less metabolic energy than skiing the run with even well executed carved turns.
Even if the skier throws in a few old-style up-unweight and pivot changes in the direction the skis are pointed (I don't want to call this a turn...), this method of descent is still very low energy.
At the other extreme, if you crank up the tempo, and ski the hill using old-school, rapidly-repeated, tail-swishing skidded "turns" with lots of up-unweighting (but maintaining the same average downhill velocity, and other constraints), you can use arbitrarily large amounts of metabolic energy.
If you are not burning calories sufficiently fast at 1 "turn" per second, make two turns per second like the crazed jackrabbit skiers many of us used to be in the 1970's when descending a steep slope. When the hill is skied this way, from a metabolic point of view, the skier might as well be doing fast twisting jumping jacks for the entire duration of the run. This technique will almost certainly use more metabolic energy than skiing the run with even poorly executed carved turns.
Anyway, it's not the clear-cut, definitive answer that you probably would have preferred, but that's my $0.02 on the subject.
Tom / PM
PS - I see that someone else jumped in with very similar comments. That'll teach me to go off and answer emails after starting a reply to a post.