Native and local resident from the district, i will be helpfull to tell you the best place to go around.
I and a cousin spent a month at Bruno's apartment on ile saint Louis. The apartment was clean and tidy when we showed up. Bruno took care of a little plumbing trouble quickly at the beginning so we could get back to enjoying our time in Paris. Like most Paris apartments it's small and you should be aware you have to walk up six flights of steps (no lift). We just took that as an excuse to eat more pastries.
While it's not fancy it is well equipped, the kitchen has everything you could need and we cooked in it everyday. The mezzanine bed was comfortable and easily fits two people. The pull out couch can be useful for a third person, but the apartment seems a bit small for three people for any great length of time. If you are interested in site seeing then this location is excellent. Easy walking to La Marais and the Latin Quarter as well as many major Paris attractions.
We didn't need to contact Bruno for much during our stay, but all interaction with him was pleasant and friendly. It's a good place to stay, convenient WiFi connection. Enjoy your time in Paris!