Mafalda's place is a wonderful place to stay in Lisbon! Quiet, yet central in Lisbon, on a residential road more than a busy party street with bars etc, which is wonderful if you want a good quiet night's sleep. However, it is still in the heart of central Lisbon.
The place itself has everything you could need and plenty of space for my girlfriend and I, with the bathroom a particular highlight. Mafalda herself was very helpful and kind and greeted us in the flat when we arrived, gave us a helpful tour of the flat and it's facilities and also talked us though some day trip ideas and good spots to visit in Lisbon.
The place is on a hill (most roads in Lisbon are hills), but public transport is is closeby and with many small shops for groceries just a few doors down the street.
To summarise, the place is perfect for a weekend or week, but be prepared to walk up the steep surrounding hills, which of course cannot be helped and are commonplace in Lisbon.