Originally Posted by DesiredUsername
A season's pass at Stevens includes the Powder Alliance and a handful of discounts.
A year ago, I would have thought it'd be easy to use free days at Timberline, Ski Bowl (both at Mt Hood), Schweitzer, and Snowbasin.
However, since they exclude Friday and Saturdays, and holidays, it's not practical for me to take time off work and travel for the limited days I could use the benefits.
So basically not useful.
The Powder Alliance benefits do not generally exclude Fridays. Each resort has its own holiday blackout periods, and the Friday between Christmas & New Year's, for example, is blacked out everywhere, I think, but generally they're valid Sunday-Friday.
To answer the original question...
For 2012/2013 I bought my Mountain High season pass because it was such a fantastic deal. I think there was some sort of perk (a weekday buddy pass, maybe?) when I bought it, and that influenced my timing, but none of the benefits influenced my decision. That season, I used the pass mostly at Mountain High (maybe 20 days or so--sadly, I work weekdays), but I also used 2 free days at Sierra-at-Tahoe, 2 free days at China Peak, and got a half-price "competitor's pass" ticket at Snow Summit.
For 2013/2014, I was considering switching to Snow Summit (despite the worse drive), but the Powder Alliance benefits helped tip the balance in favor of Mountain High--I figured if it was a bad snow year, at least I'd get some use out of the pass. And it definitely paid off! I think I skied only 5 or 6 days at Mountain High. But I used free days at Timberline, Stevens Pass, Snowbasin, and Eagle Point (they're not in Powder Alliance but were offering free lift tickets to California season pass holders), and a half-price ticket at Brian Head (again, trying to lure us even though they're not in Powder Alliance). For $250 in a horrible SoCal snow season, I thought that was a good deal.
For 2014/2015, I was conflicted because I knew there was a decent likelihood I'd be moving out of California. In this case, the Powder Alliance benefits were critical to convincing me to renew: if I stayed in Cali, I'd have Mountain High, plus the options. If I moved to the Portland area (which was looking reasonably likely), I'd have 3 days at Timberline, 3 at Skibowl, plus the options. If I moved to Salt Lake (the possibility which occurred), I'd have 3 days at Snowbasin; Mountain High available on Blackout days (I think we'll drive back to SoCal for Christmas/New Years, so this works nicely); AZ Snowbowl for a nice stop driving to visit family in Phoenix; Crested Butte for a long weekend; and some other possibilities. We'll see how it works out :)
As for other perks... I've definitely given away the buddy/midweek passes I've gotten from various promotions; I've used the ski store discount a couple times in a pinch; and I've used the tubing passes once to try it... but I've never used the early-ups (I'm just not a morning person) or lesson discounts (although maybe this year).