Are your kids difficult to handle in everyday life? Do they throw fits or run away or misbehave at the grocery store, mall, fairs, zoo near your home? If so, then I surely wouldn't expect any *better* out of them at Disney.
Outside of that, though, it sure presents different challenges when you have little legs, strollers, early bedtimes, less flexibility with mealtimes so some people advise everyone to never go to Disney with little ones. I've never yet traveled with a group that didn't have 1-3 kids under the age of 3 and 3-5 kids total. I wasn't always the one who was best tuned in to the need for mealtimes, sit-down breaks, or to just call it a day, but there has always been someone in my group who is very good at noticing those thing before it gets out of hand. My guess is that most parents are well aware of the ebb and flow of a day with their own kids.
The worst personal stories I hear are the parents who are so much on "vacation mode" themselves or want to be the cool laid-back parent, that they don't enforce any similarity to the home routine and it doesn't work out well (if you wait until every one is 1 hour past usual lunch time and THEN begin looking for a long CS line to get into, you're going to have some tired hungry folks by the time you finally have a seat and some food!)
Disney is tiring and overstimulating for adults and kids alike! If you are prepared to take breaks and chill *before* things become a problem, you can have a wonderful time!