We had a great stay at Christophe's apartment, its definitely worth choosing if you are looking to explore Lisbon on foot and enjoy being in the heart of the wonderful Alfama Old Town.
It can be quite noisy outside and due to the natural light (and lack of curtains) quite hard to sleep-in if desired. Also worth noting that getting to the apartment requires climbing two very steep sets of stairs. Apart from that, it's a nice clean space, great for using as a resting place after a long day of exploring or partying. I would recommend this place.