Pros:
Great place, 15 minutes biking from anything you're in Amsterdam to see. You can rent a bike from a bike shop 3-4 minutes walking distance from Elmar's place. Sparkling clean. Elmar himself is very nice and friendly.
Cons:
I wouldn't call these cons, but expect a rather smallish bedroom. But probably since Amsterdam is a very expensive city, for the price, it could be considered reasonable.