Way, way better. The slopestyle is a lot of fun, the kind where you can just never stop and flow through it. If you have the choice, definetely opt Stoneham for the park but St-Anne for an extended period of time or runs.
Don't cancel your trip they have lots and lots of snow up there in Quebec! I just came back from Stoneham and its fucking crazy how much snow they have compared to Montreal! And the park is really good. I can give you s description of the park if you want since I hit it a couple of times this weekend.