Vicarious European Vacation

My sister is planning a trip to Europe in May, and I've been living vicariously through her. She and a friend will divide their week between The Netherlands and Belgium, so I've started looking out for hotels. The latest issue of Travel + Leisure had some great less expensive hotel suggestions...

The Hotel Patou in Amsterdam has this quote in it's home page:

'To be modern is to have the thought, the tastes and the instincts of the epoch in which one lives' Jean Patou (1880-1936)

I'm always drawn to more modern hotels, a kind of less is more thing. And marble sinks and white duvets are a huge plus.

I came across another hotel in Amsterdam that is very budget friendly -- the CitizenM. The website made me laugh -- if you go on a tour of the room, an illustrated gal will start dancing on the bed [see below].

Got any tips for hotels in either of those countries I could pass along to her?