We had a brilliant trip to Lisbon and the flat played a part in that!
Location is great, and I loved how I felt plugged into a residential area surrounded by people getting on with their lives. Self check in via a numerical keypad lock, which meant you are not concerned if you have a late flight. Access to the centre is easy and there is plenty around to explore, including options for food and drink. If you like walking it is is perfect!
The problem is with the flat itself. It was very dirty - floors, worktops were not cleaned. The finish of the flat was also some way from the pictures and several walls were damaged with missing paint. The hob area still has rough filler around and dust was constantly dropping onto the surface from an unfinished void above. The kitchen itself was very poorly equipped - a (broken) bread knife was the only one available and we had an old, dirty washing up pad to use. No dish cloths or kitchen towel. Plenty of dishes / glasses but some wine glasses would be nice to enjoy the local produce!
The bathroom is very very small and could be shown more clearly in the listing. This could be a problem for some guests. The top of the showerhead was extremely dirty.
The studio is on the ground floor and by its very nature you are very close to any noise or activities in the streets outside. We had several nights where is was noisy very late into the night (0300). Manageable for some, maybe not for others. You can see light from under the front door!
The flat is actually perfectly serviceable as long as you know what you are getting - 2 of us were there for a week and managed fine. It is just not as clean or in the condition I think it should be.