Pros:
Amazing location (near Louvre and near most major tourist destinations without being in a touristy neighborhood itself)
Charming apartment
Good value especially for location
Good communication from host
Cons:
Exceptionally spotty and slow wifi service
up 4 full flights of stairs
nonoperational safe in room
no toiletries
Little climate control (on 4th floor would be very warm in the summer without A/C)
If you sleep with the windows open there is a large amount of all-night street noise