The staff at Bilderberg Garden were not very serviceminded. We were misplaced in a wrong room, and were just told to pack our suitcases and go to the reception. I would have expected them to offer to move for us.
We stayed in an executive room, which are located in a special wing. The executive room was bigger than normal rooms and have a spa. The ceiling had big brown stains from water damages and a cracked plate - not OK for a room near €180 per night. Internet costs a €17/24h for unrestricted access which is far too expensive.
Restaurant is very cold when sitting close to the windows. It is unacceptable that they don't install heaters between the windows and the tables. We asked to be moved away from the corner table in order to have a windows on only one side, and I had to wear my jacket in order not to freeze. We spend a total of 2½ hours for a 3 course meal in a restaurant only half full. Steak ordered medium-rare was served well-done, but was replaced within minutes (another customer had to wait for his dinner then). Dinner was overall good.
Breakfast was not impressive, but had a reasonalble variety of choices to pick from.
Staff in reception was both arrogant and rude when I had to rush them for a taxi they clearly had forgotten to order. Initially they claimed that time was only one minutes past, when it really was almost 5 minutes later "The computer says so". I allmost was late for business meeting. Only one of 3 receptionists was allowed to call for taxis (Just imagine - they have a "Taxi manager").
I have no intensions of using the hotel again - mainly because of the poor service. I could have accepted all the minor mistakes - they happens, but not with this level of service.

Before visiting Amsterdam, I was twice in UK and stayed both times at Hilton hotels. Servicelevel was impressive, and staff was very kind, polite and paying much more attention to their guests. Just imaging that it can make such a big difference.