Hey Hot. We took our DD this past Janury to a 3 day UO trip (17 months old at the time) and back again in May (a few weeks shy of her 2nd birthday) for an 8 day Disney/UO/Seaworld excursion.
She had a blast and rode EVERYTHING she could. ET, CITH, Unicorn, Woody Woodpecker (she loves coasters already, she loved watching the Hulk and DD in action).
As far as what to expect.... it's kind of a pain flying. Lots and lots of bags (we packed enough for a week for our 3 day trip). Going through security with the stroller, hiring a van with a car seat and then taking the car seat along for the rental car... that's a pain. But she actually loved the flight, which was 2 hours long.
We stayed at RPR, and Lowes hotels are great for kids. They gave her a bucket and shovel, and a nice little Fisher Price little people toy (and a bonus one under the table :>). She loved the hotel and it's heated pool. And they gave us a mini fridge for free! The woman at the desk asked us, with a wink and smile, if we needed the fridge for medication.. of course we did. We caught her drift the 3rd time she asked us if we needed it for meds.
The parks are just spectacular for kids that age too. We utilized the family service buildings, at the entrance of both parks, for changing diapers. Theyy were both very clean and a much nicer place to do the dirty work. They even have rockers there if you would like to sit down and nurse. Best of all, 1st aid keeps extra diapers on hand, in case you run out. Even better, they were free!
We did park hop each day. Usually starting out in the kiddie areas, doing a few 'adult' rides, then going next door to repeat the pattern.
DD really didn't care for any of the shows, except for Barney. And she loved the interactive play areas, especially the ones that got you soaked.
Anyway, I recommend just going and see what happens. Stay on site, so you don't have to wait in lines (kids hate that and it's even worse waiting in line with kids that hate waiting in line). Just take it slow, our DD loved exploring every little nook and cranny.
Honestly both trips were great and even relaxing. A lot of work, but well worth the effort.