Just got back from our first visit to Paris. Isabelle's apartment is in a wonderful location (it can be hard to tell from maps, etc.). The subway entrance is LITERALLY in front of the apartment and several excellent restaurants and bakeries are minutes away. There is also an excellent wine store on the next block where the English speaking staff will help you find a perfect bottle of wine to your taste and within your budget. The cheese and butcher shop on the same block are also wonderful.
The apartment itself is beautifully and tastefully decorated and "feels" Parisian. We found it clean and quiet enough for sleep. The wifi worked, as did the cable TV, after a little tinkering. The one oddity was the system for buying food. We were instructed to eat what was present in the kitchen and replace the items before we left. Since we have our own tastes and needs (for example, there were packaged croissants-- a travesty in France!), we did not eat any of the items in the pantry or refrigerator (except for water and milk, which we replaced). It felt like a highly inefficent way to go about self-catering since we watched food spoil that someone else bought.
Also, sadly, we never got a chance to meet Isabelle or Herve so we will never know how it is that there are so many pieces of interesting orginal art from a variety of artists (many with "pour Isabelle" on them). Was Isabelle a former book illustrator? A cartoonist? A book editor? That will forever remain a mystery.
Despite their absence for the 8 days we were there (we were shown the place by the housecleaner), Herve responded to texts and checked in on us periodically. They were also patient with our changing arrival dates (courtesy of the Air France strike) and offered pointers by text when we needed them. We were also able to check in quite early since our flight got in at 8:00 a.m. All in all, highly recommended and we would try and book the place again should we be lucky enough to return.