I stayed at Charles' apartment with my GF for 4 days. We met him only at the time of checking out, however everything was set up in an outstanding way.
The check in was handed over to a company called KeyButler, whose contact person was quite efficient, making it wholly hassle-free.
The apartment was very clean and fully correspondant to the pictures. There are all amenities such as flat-screen TV, a nice sofa, large windows, comfortable bed for two, fully-equipped kitchen (dishwasher and washing machine included)...
You have probably learned about the presence of the cat Borus: it's actually more "handsome" in real-life! We had a very good time in its company.
The location is also quite convenient as it is close to a couple of tram lines (13-17) which lead to the city centre in about 15 minutes.
I would definitely recommend Charles' apartment and would keep it in my list for a next stay in Amsterdam!