Antonin's place is an ideal spot for a trip to Paris! The location is excellent, near two major train stations, and plenty of good bars and restaurants. It's close to the city's big attractions via bike, walk, or metro. The space itself is stylish and cozy, very charming and clean, and my girlfriend and I looked forward to coming back each evening and enjoying the apartment.
Antonin was a great host; he was very flexible with our check-in as I was dealing with some unexpected travel delays coming to Paris from the US.
The only downside to the place was that it is at the top floor of an apartment building, up several long flights of stairs. This wasn't a problem for us (the long climb isn't fun, but ultimately not a huge deal for young travelers) but it could prove a big obstacle if you, or someone you're traveling with, has health or mobility issues.