We stayed in the apartment for 3 nights an we had a great time!
"i weiss nüme wiener heisst" picked the three of us up from the central station AND the airport (because our flight was cancelled and we arrived the next day), which was great. We were shown around the apartment, which is an arts studio at the same time :) we had bicycles and everything else we needed to make our stay as good as possible and we were given tips to visit around Amsterdam from "i weiss nüm wiener heisst".
To sum up, they were very welcoming and helpful, I would definitely recommend to stay in this apartment!