We spent one month at Charles' appartment. It is located in the best area of Paris. The neighbourhood is full of bars, cafes, boulangeries, patisseries, restaurants, shops, etc. and it is very close to Pompidou, Saint Eustache, Le Marais or the Seine, that is 5 minutes walking distance. The area is very safe and lively, apart from being very well connected by Metro or Bus. I would definitely recommend this place for visiting Paris.
The house is very good for a couple or two couples if all of them are very close friends :-). It's small but cozy and tidy and, even it's in a crowdy neighbourhood, it's very quiet, you won't hear anything at night. However I missed some kitchenware and the kitchen is extremely tiny, enough for making the breakfast but not much more.
The freezer didn't work, I guess it will be repaired. And the TV is really big, although we didn't watch it too much. It's a third floor, no elevator, and tiny stairs, but it was not such a big deal.
I would recommend it, definitely.