I would not dispute that the impact of wind upon skiing is more negative at Las Lenas than at Mammoth.
1) Mammoth's upper lifts are leeward of prevailing winds while they are frequently crosswise to Marte.
2) Mammoth does have trees on the lower half of its vertical. Adam can vouch for some impressive storm skiing powder days this past season, though there are times like my 2006 example above where the wind is so pervasive that there is not much powder left when the storm is over.
3) Windy days at Mammoth usually shut down 1/4 to 1/2 of terrain with just a handful of severe days as much as 3/4. Any windy day at Las Lenas Marte is down, which means 3/4 of terrain.
With regard to where the wind is "far stronger and more frequent" I'm not so sure. Mammoth upper gondola and chair 23 are closed for wind about 30% of the time by my 33 years and 250+ days of experience despite their leeward placement. Mt. Bachelor's Summit lift, which has a crosswind placement like Marte's, is closed about half the time during the winter months, not so different from Marte.
My impression is that wind is most frequent and consistent near the top of isolated peaks like Mammoth and Bachelor. But it's probably more localized; when it blows at Las Lenas it's more likely to affect most or all of the mountain.
Interestingly, during my 2005 week at Las Lenas I experienced little wind while skiing, though the snow conditions sometimes offered ample evidence that it had blown hard overnight.
My son Adam has expressed exactly the same sentiment as soulskier with respect to Las Lenas terrain quality vs. other Southern Hemisphere ski areas.
