The apartment is well located in a quiet street about a 10-20min walk from most touristy points of Lisbon (and a 30min from the river). It's clearly a business-built Airbnb unit, so you're not saying in anyone's apartment.
The good side is that it's all very clean and utilitarian - there's a Nespresso, there's heating, a clear instruction booklets, check-in is easy and done through a company employee, etc. The bad side is there are some small details that transpire from someone never actually having lived in the unit before (e.g. the bed side tables have sharp edges that are really close to your head when you're sleeping, the bathroom door lock is annoying to operate).
If you're looking for a clean apartment with basic amenities, easy check-in and parking, and you're willing to walk a bit through Lisbon (like we were), and you don't plan on spending much time in the unit itself, I'd recommend Carly's place.