We had a wonderful time staying at the Collector. Karel is a great host - he communicated well before the stay and made sure we had everything we needed during the stay.
He stocks the fridge and cupboards in the guest kitchen and we had more than enough to make our own breakfasts at our leisure. If you are lucky you will get eggs from his own chickens.
The rooms are well-presented and a generous size with balconies.
The location is great - just south of the Museumplein, Vondelpark and the Concertgebouw, and lots of shops and restaurants are just around the corner. On a main road so easy to get to with public transport (bus 197 from the airport) but so quiet in the room at night.
We will definitely be staying again the next time we are in Amsterdam.