Alex's place was great - close to the metro and restaurants, but on a quiet street so there was very little traffic noise. It was also close enough to walk to a lot of places, including major tourist attractions like the pompideau centre. The apartment was clean and nicely decorated. The WiFi worked well, and Alex gave clear instructions on how to check in.
There was occasional noise from the neighbours, which is pretty common in Paris, and there was some construction happening next door. It didn't bother me at all, as I was always up early, but it might wake you if you sleep in. All in all, I had a great stay at Alex's apartment.