I disagree. But I had a season pass at Sundance for three years, got married there, and return every year. It's incredibly beautiful, super kid friendly, and romantic. I love the Mandan cottages with their wood fireplaces. It reminds me of Bromley in Vermont but with Utah snow.
It is completely unspoiled and undeveloped and Redford has gone to great pains to keep it so, buying up thousands of the surrounding acres and putting them in permanent trust. It's about a 45min, spectacular drive to the Park City resorts through the Wasatch back, and about the same, smoggy-ass, freeway jaunt to the Cottonwoods along the Wasatch front.
It's quiet, romantic, has great food, a wonderful spa, and becomes a part of the woods, mountains and streams that it's set in. The skiing is pretty damn good, I think, and on a powder dump, you got freshies to yourself.
Anyway, I thought you meant Sundance the film festival at first. for that, stay at Deer Valley, wait two hours to be seated at a PC restaurant, and fight the crowds all day and night. In other words, it's the opposite.
Now, if you want double black steeps and big mountain skiing, it's Alta and Snowbird. Anything short of that, you might just love the place...