Although I did not had the chance to meet Grégory in person, he took care of a smooth hand-over, and was contactable by e-mail.
The studio is really nice, with a lot of lovely details, and it actually feels very spacious. I stayed in Paris for about four days, and the studio had everything I needed. It is perfectly located in a lively area: for having a coffee, dinner or a beer in the evening, for shopping for daily necessities such as food and although to get anywhere in Paris quickly and conveniently.
The only downside: You can not open a window, what could be a challenge in times when temperatures are high and humidity is low. I enjoyed some nice late evenings in the inner courtyard, which seems to be fine with the friendly neighbours, and a fan should be able to solve and fix this little "problem".
Grégory's studio is definitely a place I would recommend.