True, I’m mostly paying attention to Killington since it’s in the East. Perhaps more colorful opinions here than a destination resort.
I think of Killington as a "destination resort" for the northeast. There are plenty of locals who consider K'ton as their home mountain, as well as regulars from big cities who act like locals, plus "tourists" who only go to for one ski vacation. For me, that's true of any resort on Ikon or Epic in the northeast.
I've skied all four of these Powdr resorts for at least a couple days. I have the least experience at Killington because I went during early December when very little was open yet. Have skied a couple days at Copper, a few days at Bachelor, and quite a bit at Snowbird. They are very different resorts. K'ton and Copper have multiple peaks. Snowbird has five distinct sections and it can take 15-20 min to get between them. The front side and Mineral Basin have completely different terrain. Bachelor is one huge volcanic mountain with 360 degrees skiable terrain and very long runs.
Looking at the stats for the four mountains shows the contrast between them a bit. Snowbird is a favorite with locals and travelers from both coasts. Perhaps the same for Copper. Bachelor probably has a smaller percentage of out-of-state travelers who fly to Oregon for a ski vacation during holidays or mid-season. Killington draws from New England and NY/NJ/PA, which means a much higher population who live within driving distance for ski vacations.
RESORT STATS for 2021-22
Killington, VT: 1000-1500, 14 chairlifts and 3 gondolas
Copper, CO: 2500 acres, 14 chairlifts and a gondola
Snowbird, UT: 2500 acres, 11 chairlifts and Tram (100 people max)
Bachelor, OR: 4300 acres, 12 chairlifts
While all the resorts have detachable high-speed chairlifts, the average chairlift lengths and percentage of fixed-grip lifts is noticeably different.
When Powdr used parking reservations for 2020-21, it was possible to tell by early January which days were popular during mid-season and sold out well in advance. The same will be true for Fast Tracks. The blurbs I've seen say Fast Tracks will be available every day of the season.
Nov. 1 is when people will be able at add Fast Tracks.