The location of the apartment is great, it's quite central, really close to the metro station with a bunch of shops, bakeries, bars around. The apartment is on a 4th floor and the building doesn't have an elevator but that didn't cause any problems for us. It's a one bedroom apartment with a double bed and a sofa in the living room - we used both and they were quite satisfactory. The communication with the host was excellent, as I was arriving in the morning and leaving in the evening the check-in/check-out were organised so it fitted me perfectly.
I highly recommend it to everyone staying in paris!