We stayed for 3 nights upon arriving in Paris, and had a great time. The apartment is in a very central location a very short walk from Pyramides metro stop. Easily walk to the Louvre, Notre Dame, and the river. You self check-in by using door codes provided by the host. Keep an eye out, the door is difficult to spot on the street - the pictures in the guide sent by the host were very helpful.
The apartment is two bedrooms - one is partitioned off from the main room, with 18 foot ceilings, and has an en suite sink and shower (but no toilet). The other bedroom is an unusual half-height room, only about 7 feet tall, off to the side (as if the vertical space had been divided in half). Perfectly fine, although if you were taller than 6 feet it may feel claustrophobic. It doesn’t have an en-suite but is actually more private. There is also a separate shower/sink room near the kitchen, and finally a separate toilet room (the only one) near the front door. Both beds were very, very comfortable. The living room couch folds out to a bed as well (we didn’t test it). There is a combined laundry washer/dryer and an iron.
This was a great place to stay for two couples traveling together, with plenty of space.