I booked the 1 Double Bed, Private Bathroom (Cabrio) room. The space was extremely compact, with a very minimal bathroom. The bed itself was fine, nothing special.
The main issue was the lack of AC. I asked at reception and was told that the vents in the room only circulate air, they are not AC. Since I visited in August, with Paris reaching 34°C during the day, the room was uncomfortably hot at night and made it difficult to sleep.
Unfortunately, the hotel also doesn’t provide fans, which would have helped.
Overall, it might be fine in cooler months, but I wouldn’t recommend staying here in the summer.