It was a wonderful stay in the windmill of Roel - it was as beautiful as the pictures suggest. Roel is a very friendly, relaxed person and a very good host. The breakfast was very joyfull just like the whole stay.
If you travel by car to Amsterdam it is also a very good option since you are quickly in the Centre by tram and there are plenty free parking spots near the windmill and the tram stop.
I can fully recommend Roel's windmill.

The only downside was a natural one - the mosquitos near the windmill causing lots of mosquito bites ;)