Tiny little apartment in Mouraria--close to the Castelo, Se, and Martim Moniz--but not too far up the hill for tired legs! We had a lovely dinner with friends on the terrace with a view of the Castelo up the hill.
I think the only barely negative thing I could say is that like many apartments in Europe, the gate locks shut so that the only way to leave is with a key. For those with fire safety in mind, this might be a turn-off. But the location can't be beat for a feeling of living in real Lisbon, with small shops around the corner, a Food Temple vegan restaurant, within easy walking distance, etc.
Their accepting our reservation was almost instant. Check-in was a breeze, and she was even kind enough to book a taxi for us to the airport. It's a small place, but definitely beats a hotel!