I love when people just go out and recommend a ski that they didn't even mention and then give no reasoning to why they should get it and not know anything about the person...as if to say, AR7 is the answer to everything...
Both are softer skis, the Masterminds are lighter, they're both really fun in the park...but neither will be fun in the powder. You may want to look into either the K2 Silencer or K2 Domain, but are super fun in the park and can handle the rest of the mountain a lot better with their rocker (and the Domain is 90 underfoot). Also, you could look into some of the wider park skis like Anthems, Watch Lifes, Blends, and Kung Fujas - all of them are 100 underfoot (except the Anthem at 93mm underfoot) so you'll have a nice platform underfoot in the powder and the Blends and Kung Fujas are rockered to give you extra help in the powder and crud, the Watch Lifes are the lightest of the 4 while the Anthems are the heaviest.