Replying to Mammoth or vail?

I am planning a trip to either mammoth or vail over winter break next year. I was wondering which you guys think is better, Mammoth Mtn. or Vail? I ski about 40% park 60% all mtn. (I have the chronic blends), and I like powder, but I haven't skiied it too much. I have been to breck before, but I want to go somewhere else. So give me something to read. Also, if you guys have any other resort suggestions like a better choice for me, post it!!