We didn’t stay over but my god, I LOVE Efteling!
The whole place is just enchanting. We went when my kids were 10/12 and they loved all the big rides. We couldn’t get around all of the park in one day, so skipped the attractions for very small kids but can’t wait to go back and see more.
It is popular, so most rides had a moderate queue but it wasn’t to the point of frustration and every one ended up being worth it. It feels spacious, clean and friendly.
The only thing I found slightly trying was the food. We never seemed to be in the right place to find decent food and it was a long walk between the different food areas, but there was junk food aplenty. So I’d look at the maps and plot your route, and make sure you pack some snacks, especially if you have little ones that get suddenly famished!
Tbh I found the same in Amsterdam - plenty of burgers, chips and sweet treats, but not much else!
You will have an amazing time!