I have stayed with Dimitri and Marcello (and, of course, Birma, the cat) for two weeks and I must say, the other great reviews are all true and deserved.
Marcello and Dimitri really do everything to make you feel comfortable and at home, but also to make the most out of your stay in Milan.
The location of the apartment is probably one of the best in Milan, it is really central and in a vibrant and also secure neigbourhood. You can reach the metro within a few minutes, and you can reach most of the touristic attractions (Duomo, Castello, Pinoteca di Brera, ...) by foot within 15 minutes.
Thank you for everything - I could not have wished for a better apartment to stay in!