Benjamin is a very good host, gentle and quick in answering. The studio is very small (as described)! But it is well equipped and comfortable. The position of the apartment is great: in a nice neighbourhood, close to university (10-15 minutes walking from Sorbonne), few steps far from metro station LesGobellins (line 7).
Recommended!
(...maybe not if you’re taller than 180cm! You could have troubles with the shower and the mezzanine!)