We had a wonderful time in Antoine's place! It was exactly what we expected based on the description and photos. Nice big living room, fully equipped kitchen, large comfortable bed, bathroom with bathtub and shower, all in perfect state and beautifully decorated. What more would you want? A balcony, you say? I forgot to mention, there's a balcony, too! Although it's right in the middle of a busy neighbourhood close to the Gare du Nord, the place is very quiet due to its location in a back courtyard.
We didn't meet Antoine in person but he had left a bottle of wine to welcome us, and a friend met us at the apartment to show us around.
Plenty of metro, RER and bus lines are close by to take you to wherever you want to go. We mostly used public transport and only took an Uber when it got late, which cost 10-12 euros, but this is probably only an option in the evening, when traffic has become somewhat less mad.
All in all, this was a great base for a long weekend in Paris. We thoroughly enjoyed staying there and would love to come back in the future.