I stayed at Catherine's for 2 weeks and really enjoyed the experience. The flat is exactly as advertised. It's located in a typical Parisian building. The neighbourhood is great, with several shops and supermarkets around.
The flat was clean and has everything you might need. Catherine also made sure everything went well.
The only downside was my arrival. The person who was suppose to meet me didn't show up and I had to wait 50 minutes. Thankfully the next door neighbours are absolutely great and not only helped me reach the Catherine (since the phone number I had was not working) but also invited me in while I waited.