Our stay in the apartment was great. We were picked up from the airport by C&P because we arrived late but even at midnight they took all the time to tell us all about the city and nice places to see and eat. It's a tiny but very cosy apartment with a little patio. Alfama is great to just walk around with all the little streets. The city centre is a bit further away but still walkable, but you can go by tram which is around the corner or grab a taxi.
Definitely recommend to stay here as a couple.