It's been done before, and there's just barely enough clearance for them to fit without major clearance issues. Any time you put a larger tire on a quad, regardless of what kind of machine it is, you will lose bottom end power unless you gear it lower to compensate. Going from 22's to 25's you'd probably want to go 2 teeth smaller on the front sprocket. Even compensating for that, there's obviously going to be a lot more rotating weight which of course will still rob power. That extra unsprung weight will also hurt suspension performance, and the increased height is going to give the machine a real awkward stance and raise the center of gravity, making it more likely to tip.
The only real measurable benefit of going to a taller rear tire like that is if you're having ground clearance issues, and to me unless you have SERIOUS ground clearance issues the costs just wouldn't be worth that one benefit.