I had a great stay at Xavier's place. The flat is spacious, extremely clean and well-equipped. Xavier was also quick to respond to any of my messages so you will never be left stranded.
The neighbourhood is where I usually hang out when in Paris so was incredibly convenient. Hip, lively, young. You basically fall out of the apartment and fall straight into a cafe :)
Another cool point is that there is a 'secret' speak-easy on the road behind the flat - Experimental Cocktail Club, which is open late.