Thomas' place is in an amazing location and has a great rooftop space. It's a great place to relax in the heart of a vibrant neighborhood. There's plenty of space, too.
That being said, there are a few caveats I want to add. The stairs have been mentioned, but are worth repeating. It's on the 5th floor ("6th floor" for Americans) at the top of a really narrow spiral staircase.
The check-in also went really badly for us. Thomas was not there, so we were supposed to call a woman to check us in after we landed (messages or emails were not acceptable). We don't have an international number, so we had to figure out a solution using a Google phone number and the airport's wifi. But, we got no answer after trying 2 different numbers several times. We ended up sitting in a cafe near the apartment for over an hour at 10 pm trying to get in touch with someone. Eventually, we got settled in after 11 pm.
Thomas was responsive about the situation after the fact, so I hope it won't be like this for other visitors. Ultimately, we had a good time at the place, but it was very stressful getting settled in.