Harm's place is awesome. It may be one of the best options when staying in Amsterdam.
It's clean, close to the main Amsterdam touristic locations (but in a good, quiet spot), you're 'equipped' with everything you need and you can have privacy as it is basically an entire studio (at first I thought we'll have just a room and a private bath, but it turned out to be an entire, separate apartment, just for ourselves).
The only disadvantage would probably be the small bathroom, but I don't see it as a big deal.