We went in July so not much help weather wise, have been to dlp in December and it was bitterly cold!
I think Efteling is so much nicer than Dlp. It was clean, far less queues, the rides were great and there were things for all ages. We stayed in an apartment as they were still building the hotel. It's only a short walk and there was a different entrance to the park for staying guests compared to day guests.
There are so many different things to do, and wander round other than rides. My son was 7 when we went and his favourite thing was a statue of a donkey. You put a euro in its mouth and it lifted its tail and shot out a plastic gold coin from its bum 😳
The kids loved the apartment, they left sandman nightcaps for them and a bottle of 'sandman' apple juice. We all had character duvets 😁 you could order a breakfast of warm rolls, croisssnts etc to be delivered to your door first thing in the morning. They were very reasonable prices and were costed per croissant so you got exactly what you wanted. The kids loved opening the door to find breakfast.
Food in the parks was fast food but actually reasonable quality/price. We ate one night whilst watching the show, you can reserve a table in advance. It was in Dutch and they offered headsets but we didn't use them. It was very easy to follow and had jousting knights on horses and fire etc