We visited Pierre's small appartment for a week this summer. It was overall a really pleasant experience! For our arrival, Pierre had kindly prepared a few drinks in the fridge, had communicated clearly how to do the check-in and what to be aware of. He himself wasn't present during our stay, but saw to it that everything that came up still was taken care of, like a missing towel for example that he still got to us.
The appartment is on the smaller side, sure, yet it's perfectly fine for a short trip to the city where you don't plan on staying inside much anyways. Both the main room and the bathroom were clean and tidy. The Kitchen would've been fine for cooking, decently stocked, but there's also plenty of good options for restaurants in 5 minutes walking distance even, and we mostly ate out.
The apartment is also very close to the Gare de l'Est, which is fortunate if you have luggage to transport - there's no need for a bus or metro ride somewhere, you can easily walk there. This also means it's perfectly connected to public transport of course, multiple metro and bus lines are easily reachable by foot.
Our only small issues with the appartment were firstly the construction going on next door, which meant of course that it got a little loud (even with closed windows) the few mornings we did stay a little longer in the appartment; Secondly the small appartment got a little stuffy even with the windows open, which might just have been due to the stuffy weather. Both of these things will probably change in the future.
We'd highly recommend you stay at Pierre's if you plan on discovering beautiful Paris!