Karin made our stay comfortable and simple. She gave us clear instructions on how to get there and answered questions very quickly. She offered recommendations on what to see in Amsterdam and also booked us a cab for our departure at Schiphol.
The accommodations are simple but very comfortable. I've got a bad back, so I'm picky about beds - the bed here was very comfortable and I slept great with no pain! The room was very clean and there are one and a half baths - one with shower and sink, and another with toilet and sink. My wife and I had lots of room to stretch out and there was lots of room for luggage so you weren't tripping over it (important for us as we had our Brompton folding bikes with us on the trip).
We had a separate kitchenette area to eat breakfast which Karin supplied at our door each morning. The breakfast was simple (buns, croissants, juice), but kept us going well into the day - it was all we needed in the morning. There was also an assortment of teas and coffees for us to make ourselves with the supplied kettle and Nespresso-style (?) coffeemaker. There is also some cutlery, plates, and cups that are washed each day if used. You can't really make your own meals as there is no appliances, but you could prepare sandwiches, etc. The wifi worked flawlessly and fast for our entire stay.
If you are a light sleeper, you will probably be woken up early by the workers who set up the Albert Cuyp market one block over. Many of the tables, etc. from the market are stored at locations on Govert Flinckstraat where the accommodations are located. It didn't bother us, but it might bother others. The apartment is on the main floor of the building, facing the street - this is awesome for accessibility for those with mobility issues or lots of luggage, but make the morning noise an issue for some. There are about 6 steps to get into the apartment
The location was great for us - close to countless interesting restaurants in the trendy De Pijp area and walking distance to Museumplein (where all the major museums are) and Rembrandtplein (nightlife and the Tuschinski cinema). It's a longer walk to some of the other sites like Dam square, but it's doable if you are fit and have the time. There is easy access to a tram to Central Station and some of these other places, but construction made it about a 10 minute walk rather than a 5 minute walk during our stay. It was a flat 37.50 Euro cab ride to the airport (booked by Karin for us).
Overall, it was clean comfortable simple accommodation at a very reasonable amount for Amsterdam.