We enjoyed our stay in this lovely and historic apartment. Our host was very accommodating at check-in, and good about communicating with us throughout our stay. Yes, there are stairs to get to this place, but in fact all of Lisbon is full of inclines, so if you are not up for walking uphill then maybe Lisbon is not the place for you.
This apartment was comfy and well-appointed (bags for groceries, soap and shampoo/conditioner, coffee, blowdryer, etc). It was also close to grocery stores and the metro, which was very convenient for us. Highly recommend!