We stayed nights in December 2012. It was cold and snowy outside, so we took a taxi from the airport and arrived swiftly. The exterior is beautiful and the inside is modern and trendy. We were checked in fast and went up to our rooms.
The rooms have a good size, the bed was comfy and there was a small window leading to the front street. There was some light coming through the window at night, so the room was never completely dark. Not a big issue for us, but some people might be bothered. There was also very little noise from the street and the halls, again, not an issue at all but pickier travellers might have a problem.
The location was good. Not to near from the sights and attraction, the hotel is located to the east, in a more residential area but very nice. Transport is incredible in Amsterdam and a tram went from the hotel door to the centre and pretty much anything you could think of doing in the city. The area also has a great market on the weekends, several restaurants and bars.
All in all, I think this is a very nice, comfortable and convenient option for your stay in Amsterdam. Perhaps the only improvement would be to include breakfast.