The good: The hotel is in Montparnasse, at waking distance to the centre. Metro and bus downstairs.
Small room but with almost everything that you would need. Not sure why they do not add a kettle in the room as it is very cheap. Nice, older furniture that could use a change as some wear and tear is visible. Good water pressure. Also, some of the staff was very friendly even with the limited English.
The bad: the hotel is under the metro line so you can hear and feel the vibration of each passing train. I was on the 4th floor and the noise and vibration was bad; I cannot even imagine on lower floors. Also, you can hear a tone of noise from other rooms.
One other thing that I found personally very annoying was the fact that the hotel door is closed during the night and there is nobody at the front desk. I personally enjoy going for a run early in the morning but on some mornings this was not possible as there was nobody to open the door. In the ones that I could find somebody at the front desk, they were very unpolite and annoyed about the fact that they had to open a door for me. Really not cool.