Paris, 10th visit for me, but 5eme is the first. I think, I would never stay at another arrondissement.
5eme and especially "Chez Constance" provides everything to an Airbnb stay. City life as a resident is really easy and joyful there. Room is basically a loft at 4th floor (w/o lift) but entrance floor is quite enough and larger than a standard hotel room. You will also find a waffle maker in the house. All amenities are exist which you'll need even if you plan to stay long. Metro station is 2 mins away, RER 8 minutes. Thank you for everything Constance and V.