The place is nice (and small), light and well decorated.
Kitchen is not really good for cooking, just one very tiny casserole, maybe enough to make a single pack of noodles.
Great place to stay if you want to see what feels more like "real" Lisboa in a nice neighbourhood, feels very quiet and safe at night but you could also find a bit of nightlife during weekends.
The biggest problem for me was not the paper-thin walls (Yes, you will hear your neighbours but luckily they were quiet during my stay) - but a tapping-sound from the water pipe which comes and goes.
Not an issue during daytime but very, very audible when in bed, in the middle of the night.
If you don't mind that and sleep easily, this is a good place to stay.
Didn't ruin my stay but it seems dumb - I think the water pipe leading up to upper floor could just be cut off and removed, as there are no sink or running water there anyway, this might help on the noise.
Other than that, good one-week workation stay for me, feels perfect when single, should also work fine for two people.