I've been going to WDW since September 1971 and have lost track of just how many trips down there I've been on (at best guess, probably 20+ over the years). Only had 1 bad trip but that one was NOT due to Disney... in point of fact, they made everything as much "better" as was possible.
Went down in January 1996 with my then-future-wife (since divorced, thank God), my parents, & my brother (age 22 at the time). Had 2 rooms at the Beach Club, everything was going fine. However, part way through the trip (think we were scheduled to be there for about a week if memory serves), my father in the middle of the night became VERY ill. He'd had cancer surgery in May 1995 and was "done" with chemo, but was still having some problems. MMy mom started pounding on the connecting room door at about 2am saying we had to get to the hospital and do it NOW. Keep in mind, dad is a physician, mom's worked in his office (at the time) for over 25 yrs, and I'm a paramedic. When we're all going we need the hospital, it's definitely QUITE urgent.
I called down to the front desk and told them we had to get to the hospital right away, could they please have someone bring the valet parked car to the front, and please have some directions to the hospital for us if possible when we get down there. As an aside, yes, I'm a paramedic, but I do NOT call an ambulance unless there's something that they'll be able to do that will make a significant difference en route (it's just like dad being a physician will NOT go to the hospital unless it's really essential... professional bias, I know).
Not only did the front desk clerk RUN and get someone to pull the car around, she left the front desk completely unstaffed (there was only 1 person working the lobby at that hour), RACED upstairs with a wheel chair, and had it there (without our having asked for it, or even knowing we could have asked for one!) before we'd all finished throwing on traveling clothes to go down to the car. She assisted us with directions, etc, and made sure that we were as set as necessary, including asking repeatedly if we wouldn't prefer for her to call the Reedy Creek Emergency Services and have them take him to the hospital. Back then, I'm 99% sure that we didn't go to Celebration Hospital, but went to whatever was the closest at the time (Florida Hospital?).
Dad was examined and treated by the staff at the hospital, they woke up his hematologist (blood specialist) in NY, etc, did everything that they were supposed to and got him well enough to be brought back to the hotel, though not really being up to continuing to tour WDW. Still, he definitely did NOT want to go home yet, for many reasons including the fact that he had barely enough hemaglobin (the molecule that carries oxygen in your blood) to fill a thimble; he would NOT have been up to SURVIVING the flight back to NY at that time anyway. So, we stayed the remainder of the trip doing what we could. Most notably, to help improve things, the Mousekeeping staff of the Beach Club sent him up Chicken Noodle Soup from Beaches & Cream daily to help speed his recovery. They could NOT have been any nicer or done ANYTHING more to help.
To add insult to injury, on the day we were to check out, a MAJOR snowstorm hit the NYC area that morning, something like 20-25 inches of snow. I'd already checked out of my room (since the airline had still been saying that they were flying, that we'd be in business for going home, etc), but luckily because my dad was still moving at 1/2 speed (at best), they'd not yet checked out. The Beach Club staff extended my folks for an additional night and gave me another room to stay in (different floor & wing, but, at least we had a place to stay!).
We finally got home to NY, the car service managed to pick us up, etc, and we get delivered back to the house. BUT, even though the house was SUPPOSED to have been plowed, it hadn't been touched and the top layer (of about 20+ inches worth of snow) had turned to ice. Needless to say, it was a ton of fun trying to get dad inside via the front walkway & front door (couldnt even get NEAR the garage door's lock to open that door, the driveway was too steep & too slick.
I started to dig the driveway out (since I was definitely worried that my dad might need another trip to the hospital at some point). Luckily, our neighbor had a power snowblower (MUCH more powerful than the 25yr old model that we had) and loaned it to me to let me finish clearing the thing. No sooner do I manage to get the driveway clear enough for me to drive out of if necessary (I'm still a NY'er at heart, plus driving an ambulance for a living at the time, there are few challenges that I don't feel I'm up to if I HAVE TO do it), and my mom comes out and says that she'd called my grandmother (same city, but the other side of the city) and that "she wasn't sounding right". My mom asked if I could please go over there & see if she was ok. So, off I drive to her apt. building and get up to her apt to find out how she was.
She had a SIGNIFICANTLY altered level of consciousness (didn't really know where she was, not sure who she was, etc). So, this time I actually DID call an ambulance (they could run tests to possibly provide some treatment that might change her condition before we got to the hospital) and they took her over.
All in all, NOT what I'd call a good vacation, but, I will say that the staff at Disney definitely DID do everything humanly possible to make things better.
Just to wrap up the story, dad's now an 11+ yr cancer survivor, celebrating his 70th birthday next month. Grandmother was with us for over 5 more years. I married the girl I was with at the time, but, finally got smart and we were divorced a few years ago. Now, I'm VERY happily married and taking my wife on her first trip to Disney next month (yes, of course, back to the Beach Club!). So, I'd say everything ended up working out.