Arnaldo and his team were very responsive and welcoming and Alfama is the most charming of neighborhoods.
While I recommend the apartment for most, I would discourage those who are noise-averse (or don't have noise-cancelling headphones and white noise generators at the ready). Upstairs neighbors are lead-footed past midnight and the downstairs restaurant starts making noise (whiny plumbling, loud talking) at about 7am so plan accordingly if you are a light sleeper. Other potential downsides are pokey internet (4mbit/sec for those who are going to Lisbon for fast internet) and the windows look out onto a alley that currently has construction so not much available natural light.
Perfect place for short/busy visits when you want the heart of Alfama and Lisbon at your doorstep; perhaps not for those on a meditation/writing retreat.