The location of Diogo's place could not be better. It's easy to walk to all the great sightseeing locations but is very quiet at night. You can still hear the tram run on the tracks but they run infrequently at night. Also, the location is easy to get to via car, which made getting there and leaving simple. Tip: there's also a set of public elevators very close by that takes you up 3 floors, making it very easy to get to the Alfama side.
The apartment is up 3 flights of stairs. The place was sparkling clean except the bathroom did smell a little, possibly because of the heat. However, it goes away after you run water/flush (it does come back though). The air conditioning was a big plus. And communication was excellent.
Highly recommend staying here!