The flat is very central (close to Restauradores metro and the Bairro Alto - just down the hill from São Pedro de Alcântara miradouro), clean and simple. As a solo traveler it was perfect for my needs. There is a nice size kitchen and a small balcony. Overall I had a really nice stay there.
Some things to be aware of: the flat is right at the top of an apartment building so lots of stair to climb! Also, during the time I stayed (Oct 2021), there was construction work happening in an apartment below as well as in a building opposite, so it was very noisy during the day.