I think this one is definitely a matter of opinion. You can take your kids at any age and have a great time, but it depends on the plan and your attitude. We took a quick 3 day trip with a 2 year old, and it was miserable. But.. if you took that same toddler for a week, and you could space out the days in the parks with rest days, you could have an amazing time. I always say 2 things about this: Get up early and avoid the crowds, taking a break in the middle of the day, and take a day off from the parks and sleep late / swim about every 3rd day. Have fun - its the best!