Overall: Great apartment, excellent location, strongly recommended for up to four people. We arrived earlier than the scheduled check-in time, and the owner was gracious enough to let us in, leave our bags, wash up and go out.
Pluses:
1. The location couldnt be better, despite the steep roads all around. The apartment is literally minutes from all of the places you would want to see and experience in the historic areas of Lisboa, and close to all manner of restaurants, with the added bonus of a convenience store around the corner.
2. Dual-paned windows keep it quiet even with revelry in the streets.
3. There is an elevator, which we realized is a big deal because not all rental apartments have one.
4. The rooms are of a good size, and despite it being an older building, it has been kept very well-maintained.
5. Large closets with hangers, so you dont need to live out of suitcases.
6. All the mod-cons, including a coffee machine, a large refrigerator, a microwave (its on a low shelf, though, but not an issue).
7. Roomy bathrooms with plenty of counter space.
The only issue that I wished for was a light inside the bedroom closets, but that is a small matter.
If I were to visit Lisbon as a tourist again, I would reserve this apartment in an instant.