My friends and I really enjoyed our stay at Alexis' apartment. It was in a great location to explore the Marais - we were never more than 10-15 minutes walk from the many bars and restaurants we tried. The apartment is also only 2 minutes walk away from the metro. Everything was spotless when we arrived and the mattresses were exceptionally comfy!
We only had one issue in regards to unlocking the door using the automatic locking system - there is definitely a knack to it!
Would definitely recommend as a base to explore Paris.