We had a great time at Martin's place. The apartment is a good size, with the bedroom especially being very spacious. The kitchen is well equipped (including a dishwasher), there is a washing machine and drying rack, the living room has a comfortable sofa for lounging, and the bed is huge. While there is no air conditioning, we actually found the apartment to be quite cool even in June. Martin or his friend were quick to respond to messages and there was an entire desk of pamphlets and tips for things to do in the city laid out when we arrived. The location is also great - close to the metro, restaurants, cafes, etc, but not as crowded as other areas of Prague. I would absolutely recommend this place to others and would love to stay here again!