If you're like me, then absolutely you want an apartment with a/c in July in Paris. I don't need it so I stay inside in the cold all day, it's more for the peace of mind that I have someplace to escape the heat if I need to. I sleep better when I'm cool, and I don't want to waste a minute of Paris time sleeping more than absolutely necessary!

I've rented places from Vacation in Paris since 2006 and would probably rent from them again because I prefer to stay in an apartment versus a hotel when in Paris. I've been disappointed by the fact that some of the amenities I pay for don't work when I get there, despite reassurances from the office in New Jersey that they will. We lost a whole refrigerator's worth of food when the refrigerator quit. Calls to the local manager went unanswered until Monday morning, and very expensive mobile phone calls to the New Jersey office on a Saturday didn't accomplish anything. My experience is that while I pay more for an apartment with specific amenities, neither VIP nor the owners take responsibility for things that don't work, yet I still pay (in advance) as if they did, and I don't like that.

YMMV