I recently traveled with a group of four, and this was a surprisingly large and comfortable apartment in a very convenient location near Rossio. The apartment was very clean and well kempt, check-in/checkout were a breeze, the view off the living room was gorgeous, and overall we had a wonderful stay.
It wasn't an issue for us at all, but it's worth noting that there are a lot of stairs both leading up to the building and four flights to climb to get to the apartment itself. In the summer heat, it may not be ideal for everyone. Otherwise, I highly recommend this apartment.