Staying in this AirBnB will give you a sense of what living in a Parisian attic was like - albeit now you'll be in one that's been renovated for modern use. Beams and sloping ceilings give architectural interest, but are also high enough in the living room that you don't feel cramped. The bedrooms are small but fine for most travelers, and the beds were comfortable.
I appreciated the updated sink/bathroom in the main bathroom ... the rainfall shower and the view out over the rooftops made it quite relaxing.
You should be comfortable climbing up quite a few flights of stairs if you're staying here. We're fit, but those who aren't might struggle a bit.
The kitchen was well-equipped, and we made breakfast daily, accompanied by fresh croissants and pain-au-chocolate from the boulangerie that is a 5 minute stroll away.
The location is great ... in 5 minutes you are over and running along the Seine, and in the summer, it's light by 5:30am, so you can see incredible views of the buildings reflected in the water if it's still. It's about a 10-15 minute walk to Notre Dame. On warm weekends, the walkway along the Seine is crowded with walkers, roller-bladers, cafe-goers, readers ... it's lively and fun. Rue St Antoine is also just a few minutes away, with a convenient Monoprix for grocery items, along with several open air veg/fruit spots where you can purchase beautiful items. We also walked to several very good restaurants, including Le Colimacon, for memorable meals.
We always rent places with a washer/dryer so we can pack light and just wash as we go, and there was a problem with Stephanie's washer when we arrived. However, we were made aware of it on arrival, and Juan Carlos & Stephanie found a way to help us out that was thoughtful and avoided the need for us to head to a laundromat.
Check-in was easy as JC met us on arrival after we texted him from Gare de Nord.