This is a fantastic location. It's on a quiet street overlooking a lovely courtyard and very close to the main attractions in the area (as well as the hop-on hop-ff/tour busses and trams). The only caution I have is that, like many places in Lisbon, it can be a bit of an up hill hike to get to the apartment from any direction (this didn't affect us, but please keep in mind if you have any mobility issues).
Manuel was a great host and very attentive. We arrived in Lisbon early in the morning and were able to arrange to have our luggage stored at the apartment prior to check in. This left us free to explore right away and check out some of the recommended sights and restaurants Manuel provided before we arrived (I definitely recommend Sacolinha as my café of choice)
Though we didn't spend much time in the apartment (other than sleeping), it is a very good size with a lovely kitchen and large windows overlooking the balcony/courtyard in every room. The amenities were great and having laundry facilities in the apartment was definitely a bonus and let us minimize what we needed to bring.
I definitely recommend this location to anyone wanting a home away from home in Lisbon.