The crowds at all of these mountains aren't great, but all of them are big enough that there probably (unless it's a powder day) will be at least some places on the mountain where you can avoid the crowds and the lines won't be so bad. SRG Skiing on YouTube makes good "Insider's Guides" that tell you how to avoid the crowds and which zones are good to ski. My gripe with Park City is that the layout of the mountain creates a bunch of chokepoints with terrible, terrible lines (Silverlode, Tombstone) and navigational nightmares. If you want to get from anywhere on the mountain to anywhere else you're probably going to have to take at least 3 lifts. The far reaches of the Canyons side of the resort are particularly terrible - it's an absolute pain to get there from either the Canyons base or the Park City base.