If you can move your dates, do. It will be quieter. As a family, we always used to go for three weeks around easter, and the two weeks that fell in the Easter Holidays were always much busier at the parks, most notably at Universal I'd say. Disney is busy whenever you go, it'll just be busier. But at quieter times of the year (like early June when we go now), Universal is much quieter. We went to Universal Studios one day, got there for the gate opening, and had done five or six of the big rides with less than 5 minutes standing in line at each, and had done them within 90 minutes I think. So the rest of the day was quite relaxed as we knew we'd done the main rides, but did some again anyway because for some the queues never got that busy. Easter weeks were a whole different storey, where we could be waiting easily for an hour at the bigger rides. It won't be the end of the world if you go at Easter, you'll just be waiting in queues for longer.