I had a fantastic stay with Guillaume that exceeded all expectations. Good news: the ZEN room lives up to its name, with a lot of space, cool temperature in the summer, and a lovely French balcony which guests can use to work on a laptop, eat breakfast, drink beer and smoke cigarettes (if they so choose). The wifi Internet speed is wicked fast, and the apartment itself is located next to a major commercial center (H&M is only a few minutes away, folks...) and a major transportation center, the Gesundbrunnen Station, which provides U-Bahn, S-Bahn, AND trains for inter-/intra- country long distance travel. If you have not visited Berlin before, you'll very soon recognize the amazing convenience of having so many transit options so close to home.
But, the best part of all was the superior hospitality, unflagging friendliness and special care offered by the host Guillaume. He not only allowed me to use the laundry but cleaned my clothes for me (!). He often said hello every time we met in the apartment or went out to leave, and always asked how I was doing and if I needed anything during my stay. Also important for the international traveler is that Guillaume happily answered any questions about good locations for food, coffee, and getting around the city; in this sense, he acted as both tour guide and consummate host. We even had dinner a few times and chatted over some beers. Perhaps the best compliment I can give is I consider Guillaume a friend.