I agree with Metro. Just enjoy one park and see as much as you can. The bonus will be that you save some $$. You can always come back for the other park!
IoA in particular has incredibly themed lands, and the Port of entry has so many details, it is a pleasure to stop and smell the roses. There are so many rides and so many great places to eat, if you just do one park, you can see more of it and have extra bucks for souveniers!