ark City's park does have more people in it, I will grant you that. On occasion the line for Pick 'n Shovel does get slightly long I will also let you have that. However, I have rarely ever had to wait to hit any feature at Park City.
I would rather ski in a slightly crowded terrain park with really good jumps than ski in an uncrowded terrain park with poorly constructed ones. The jumps at The Canyons really do suck big time. Their rails/boxes are pretty fun, but their jumps are horrible.
If you ever ski Kings Crown you will realize that there is sometimes almost a lack of people in it. It is nice to have people around so that you can see how fast the conditions are, and so that if you do get hurt you aren't alone waiting for someone to find you. I would hate to be at The Canyons where you feel that way almost all the time. Kings Crown is almost never over crowded and the payday lift line is only crowded at Christmas.
The Canyons moving their entire terrain park to Saddleback is really going to cause some crowd problems though. That is the only crowded lift at The Canyons, and now it will have 2 or 3 times more people on it. Good luck skiing more crowds than you are used to in a sub-par terrain park. At least when Pick n Shovel gets crowded we have the option of hiking the pipe or riding Kings Crown.