My kids adore Centre Parcs - although we go to the French ones these days for better weather (and a bit more of an adventure). We go every year for a week.
They like that they know what to expect, that we can go swimming every day (sometimes multiple times), we book well ahead so normally get a free activity, plus we go bowling, get one of the weirder meal deliveries (fondue, or steak on a stone), I give them 20 quid for the arcades another day, we hire or take bikes (DS1 learned to ride at center parcs), mine love the buffet, and one meal a day at the buffet sees us through with breakfast and a small something for dinner/lunch (which we often pick up on the way from Costco so it's super-easy for me).
We get way more enjoyment and exercise than we would from a drip to disneyland, so it's horses for courses really.
People do speak highly of that theme park in the Netherlands, but mine are a bit old for that now, they way prefer the slides and waves and rapids and outdoor pool at Center Parcs (and when they were little, they loved the splash pad bit)