I've stayed at the hotel for two nights and as for such a stay it was perfect placed in the center within a walking distance to Ann Frank's house or Amsterdam Centraal.
The low price was an additional plus of the property as well as the building itself, which is very nice to an eye.
For some, lack of the lift might be an issue, as the staircase is very high with a lot of steps, but that is typical in Amsterdam's old buildings. For me it was an additional charm.
I've stayed in a room on the last floor (more steps = better workout ;)). It was small, but comfortable with a great city view and balcony to enjoy the city from. Small, but well designed bathroom was just enough for my needs. There was a safe in my room, so I could store my valuable items as well.
Breakfast was very nice, could be enjoyed on a terrace with a city view :)
Overall, I am very pleased with my stay at DiAnn.