The W22 is not expensive considering what you get in return.
Our room was quite big, the bed was comfortable, and we even had a bathtub!
You're not in the center-center, but if you don't mind the short trip with the metro, that is no issue whatsoever.
We did not get the room that was shown on Airbnb. However, the one we did get had the exact same themes and looked just as nice; all it missed was the balcony/view.
All in all: good stuff! We will definitely stay again if we come back to Berlin.