Katja's apartment is a very nice studio, perfect for 2 people; as duch people would say: it is very "gezellig!". Katja was not around during our stay because she was participating at the NYC-marathon (with a good cause!) However, she arranged everything before departing so we could always have a contact person, a friend of her was waiting for us at our arrival and gave us the necessary instructions and tips to move around the neighborhood. Her mother picked up the apt keys at our departing, she was very friendly and nice to chat with.
The apt. was very clean and everything was ready when we arrived: clean towels and bed sheets, there were instructions for how to use a nice coffee machine, etc. and a toblerone candy bar as welcome package :)
The apt was as showed in the advertising pics. It is located next to the amstel river in a quiet area, but with near (within a walking distance) pubs and restaurants. The amstel train station is barely 5' walk away and it was very straightforward to go downtown. Renting a bike for transportation is the best, the museumplein is less than 10' and the city center 15'.
Communication via email was easy and fast. Katja replied promptly to any of our inquiries.
We would definitely stay here at our next trip to Amsterdam.