Took our little one at 5 months and then again a few weeks ago at 15 months. Both ages were SO MUCH fun!! People thought we were crazy, but being Disney addicts who have gone dozens and dozens and dozens of times over the years we couldn't wait. We knew to expect a totally different experience, go slow and just enjoy being there. Know you can't do everything, it'll be different and that sets the pace I think.
Didn't use a sling ever, hated 'em and so did baby. Used a stroller or we carried him, this time he's walking some of course. (Read: RUNNING)
Used the baby care centers when we could, they are so much nicer and easier than regular changing table in restrooms. BUT, if you're across the park it's not worth the journey. Have something to lay baby on, while on changing table. They are hard, metal and cold. We used the stroller to change alot when he was 5 mths b/c we had the big ole stroller that laid back. This trip we had the light one that didn't.
Both trips we spent mornings at the park until about noonish and then left for lunch or right after, we ALL took a long nap and then headed somewhere for the evening. EVERYONE was much happier after a nap!! We took swimming breaks too while we were back at the resort, both trips!
We took him on TONS of rides, everything we could both trips. I made sure I had something in my hand to distract him if he got upset. A bottle 1st trip or sippy cup this time with juice/water. A container of snacks, paci, toy, something to take his focus off if he got upset. Happy to say we never needed anything other than this trip on the "Great Movie Ride" simply b/c it's longish and he was getting tired, we needed a snack to keep him calm. We should have left before trying one more thing that afternoon
Characters were his favorite part BOTH trips. First time I'd booked a few to see how it went. He LOVED them so we booked more! This trip we booked a ton and he adored them. I agree characters take a ton of time with babies and love to play with them, made for great photos I agree. TRULY TRULY his favorite part!! Character meals were SO VERY worth it!!
We drove and were able to take so much garb both times. Diapers, wipes, bath tub first trip, strollers, toys, formula/bottles first trip & baby food and bumbo seat. This time sippy cups, bottled water, snacks and toddler meals. We move into our resort big time. We stayed for 2 weeks this trip
We also found it was better to just sleep with him than use the pack n play. He would wake up crying both trips at 5mths & 15mths. Just somewhere different. So we just pushed one bed up to wall (we were at Port Orleans Riverside) and then took turns sleeping with him. Parent on edge, baby in middle and then wall. You can ask for pack n play and/or bed rail. We had both, but didn't use either.
For a toddler I'd take plug in covers if I had that to do over again. Will remember for next time

You wont have to worry about that though.
Have so much fun!!!!!!!!!!!!