We also get park to park. It's just easier since we like to visit WWoHP in the morning and then go over to the Studios for a while. The Studios is our favorite park.
Considering your answer two days would probably be enough but be sure to get there at rope drop. I still enjoy a more relaxed style of touring but if you go pretty hard and can keep up the pace then more power to you!
Thanks for reply Planogirl. So interesting to hear US is your favourite - what a (refreshing) change from everything I read! Why is that ?
Don't think we'll get there for rope drop on our first day, considering everything we have to do on that first morning. (leave prior hotel, late previous night, won't be able to wake kids up early first morning, etc). Would you start off then at the Studios in that case (it'll be Sunday Dec. 5) - in which case, if we don't get park to park we'll miss out on late hours of IOA that day (and only day of late hours at IOA during our time there).