Hi Jennifer,
There are so many choices when it comes to
Walt Disney World Park tickets - how many days, which optional add-ons to chose, and so on.
My family and I go to Walt Disney World and to each of the four theme parks multiple times per year. Even having been there so many times, we have yet to see everything at every park.
That said, there is some appeal to going four days - one park each day. You could certainly set up your trip so that you planned to see the highlights at each park. Choose a few attractions at each park that your traveling party really wants to see, and then be sure to see those, one park each day. Realize that you will not be able to do every attraction at every park by visiting the parks for one day each - and that's okay. Choose the attractions that the most appealing to your traveling party and really enjoy those.
Even if you do go one park each day, I would suggest adding that fifth day. That way, you can go back to the park that you enjoyed the most, experience your favorite attractions again, or maybe even take in some new experiences. Remember that the price per day of a ticket goes down each day that you add, so adding the fifth day is incrementally less expensive than adding the second or third day.
If you are concerned about the price of adding a fifth day, I suggest that you consider if your traveling party really needs the Park Hopper option. I enjoy having the Park Hopper option for the flexibility of going from park to park on the same day; however, if you are planning to one park per day you could save money by getting a base ticket instead, which allows admission to one of the four theme parks per day.
I hope that this information helps with your decision, Jennifer! Please do not hesitate to ask if you have any further questions.