Strengths of the apartment:
The location was fabulous. You could walk to any sights within Baixa, Bairro Alto, Chiado, or Alfama (with hills of course). A few steps from Rua Augusta. Just a couple of minutes to endless restaurants, the river, the cathedral and more.
It was roomy for a central place - the bedrooms were reasonable, lots of storage, the living space felt generous.
It was easy to get into with the contactless-method.
Beds were very comfortable.
Place was clean.
Bathroom was great and hot water was plentiful.
Challenges:
For the price, it did feel like furnishings could be up a notch in terms of quality (e.g., couch; the dining chairs were so loud if you moved them an inch).
As others mentioned, there was a strange odor in the apartment; you adjusted to it, but noticed it each time we entered the apartment or the bathroom.
There were 88 stairs from the entrance to our 4th floor apartment. Most of the time this didn't bother us, but...
The elevator was broken. There's a sign that says that they are waiting for repair, but based on prior reviews this seems to be the norm. Bringing luggage up 88 stairs wasn't ideal.
Overall a lovely stay, just a few things that could make it even better.