This was perhaps one of the most easiest time when renting an apartment. The landlord spoke English!!!! He contacted me several hours after the request, he was so kind as to write special letters for the embassy for me and my friends and which is more, he agreed to be paid upon arrival as there were problems with bank transfer.
The landlord also sent me a letter in Chinese to show to the taxi driver so that he could easily find the right place! We were met by a nice English-speaking man, who gave us key, explained everything about the flat and disappeared (which is a great plus, to my mind).
The flat is in a nice and quiet place, not far from main attractions and so I highly recommend it as a place to stay in Beijing.