João's place is excellently located in Alfama, it is in walking distance to Martim Monez, Rossio, Bairro Alto, you name it. The place is pretty big! The main bedroom has a lot of space. I didn't have any issues with it except for the wifi not working on the final days.
One thing I will say is avoid walking the narrow path down to Martim Monez, the street is extremely narrow and there are many questionable looking people lurking around there. Stick to the main road which has the tram tracks on it when you're going to and from the house.