We had an excellent stay here. The flat is clean and tidy and reasonably sized for 2 people (though reviewers are right in that it is smaller than the pictures suggest). It is a nice place to stay and very standardised - you can expect cleanliness and consistency, though it is a little lacking in character.
The location is also very good. The flat itself is situated on a back street and the windows look over some old dilapidated flats, which didn't bother us. It is near a very nice Pasta restaurant (Pastaria - would definitely recommend) as well as a metro stop and a reasonable walking distance from the busier touristy areas. Check-in/check out was simple. The flat also had things like a kettle, microwave, washing machine, hair dryer etc, which was very handy.
It would have been nice if some basic essentials had been provided eg Salt and Pepper, a Corkscrew/bottle opener, washing up/cleaning equipment etc.
Overall I would definitely recommend the stay! We were very happy here during our time in Lisbon.