We’ve stayed at Fort Wilderness and gone to Universal several times. For us Universal is a two day visit – one day for each park – Universal Studios and Islands of Adventure (we haven't been to the water parks). We’ve always gone during a non-busy time of year so we never bought the additional ride reservation system. If you're going during a crowed time or only plan to spend one day you may want to consider the extra cost (the Harry Potter lines will be loooooong). As others have said they are separate parks so they have different ticket packages. Read all the ticket options carefully (single day, multi-day, multi park, etc.).
Traffic and parking can also be a hassle (and cost) so we’ve used Mears Transportation to go between Disney and Universal Studios (http://www.mearstransportation.com/services/shared-ride-shuttle/).
We're going back to Fort Wilderness for the Christmas lights this year but do not plan to visit Universal this time.
