We chose to stay with Krystel for easy access to Gare du Nord train station and majority of the lines. It is a clean, lovely place, as described with a comfortable sofa bed. Krystel was easy to communicate with and provide detailed tips on getting to her place and checking in (so helpful!). The only downside is the level of noise throughout the night due to being close to the train/bus station on one side of the apartment and busy road on the other side so the light sleepers in the group struggled a bit but otherwise everything was great!