Just back from our second stay (in two different) Cobblestone Paris rentals, and I would highly recommend them. Greeter was friendly, informative and available for questions/issues. Plus offered several recommendations. Had a wonderful stay in our temporary Paris home!
Did you ever use French Bee for you travels?
https://community.ricksteves.com/travel-forum/transportation/french-bee-ewr-to-paris
No, I haven't. Got a great fare on United from EWR this time.
Thanks for posting about Cobblestone Paris rentals. It really helps to have alternatives to AirBnb and VRBO which have gotten a bit big for their britches.
There are posts here about Guest Apartment Services which also seems great--only 38 rentals managed by a rental company all located in the Marias. I've just rented one on Ile Saint-Louis that is actually a bit cheaper than the RS-recommended and reasonably priced hotel that I had reserved and canceled once I read here about GAS.
Thanks again. I hope others post about the jewels they've found.