There was a wedding reception on site and music and guests were quite loud until 1am. A little unexpected since there is midnight curfew to keep out the partying crowd. Tried to take local train to Amsterdam but ticket machine didn't accept credit cards and we didn't have enough Euros (plus a little pricey) so we ended up driving the 30-45 min into the city. Once guests wake up in the morning, be prepared for a lot of door slamming and loud voices in halls. If you are a light sleeper, pack the ear plugs.
We were a family of 5 (kids 4,10,16) and we stayed in an 8-bunk room in the main castle. Make sure to request the castle or you could be played in the separate, adjacent bldg. it was our first experience in a hostel. Very clean and beds surprisingly comfortable (suggest packing a few extra blankets). Shower is very utilitarian but water hot and plentiful. Bring all toiletries as there isn't anything provided. Grounds are beautiful so allow time to walk outside and take photos. Typical Euro breakfast...rolls, cheese,yogurt, hard boiled egg. It was a unique stay for one night and our kids can say they slept in a castle. Next time I would pay a little extra and stay within Amsterdam, however.