Ivan's place is beautifully furnished and within easy walking distance to most places (about 30 minutes to the Anne Frank House and different Museums).
The stairs are very steep, so be prepared with the luggage however we had no major issues. Like most older buildings in Amsterdam, noise travels. We had other renters above us that were so loud and partied well into the night - obviously not something the host could control - which left us a bit exhausted from lack of sleep.
Overall, a very decent apartment in a nice location We couldn't use the kitchen for safety reasons and Ivan was difficult to get hold of prior to check-in, but still a good place to stay.