We had an overall nice stay @Kim's place. It's clean and modern (even thought it's located in rather old building, contrasting with a state of apartment).
Location was close to the city center, what was convenient. We probably could have do a better research about Graca area (so no offence to host) to know that it's not a prettiest area in Lisbon - rather old, dirty and IMHO not too safe (at least we felt not that safe in the night). Still, it had its charm and I'm sure that some travelers might love it.
Apartment itself is stylish, really clean and in a good state. It has a lot of convenient amenities, all pretty new. Keep in mind that one bedroom has no windows or ventilation (it wasn't clear for us on pics while booking). Doors have rather poor noise insulation so better coordinate sleep/wale-up time with your co-travelers :).
For the check-in, please keep in mind that even if you put correct address in google maps, you might be directed to the wrong location (it's Travessa... NOT Rua...). As it was our first visit in Lisbon we were not aware of the difference.