Overall, we had a great stay at Tina's apartment. The place was a bit hard to find, and as others mentioned, some people may find it difficult to climb up several flights of stairs. But the location was unbeatable - just steps away from Chatelet - Les Halles metro station and within walking distance to major attractions.
The apartment itself was sufficient for our 4 night stay. It's a studio with a small toilet and a small shower space. Two suggestions that would improve the stay: 1) more supportive pillows and 2) fixing the shower door so it won't leak water.