My overall impression was very good. It's a perfect place to stay in Lisbon for a solo traveler or a couple. It totally matched my expectations and I was happy to stay in this apartment despite couple of really minor drawbacks.
What I liked :
The location is awesome, in the most charming part of Alfama, very close by foot to the most pleasant and interesting sights - I was enchanted every morning when I was walking out the apartment or in the evening coming back. The scent of orange blossom and all that beautiful wall paintings in the surrounding streets were very spitit-lifting.
The place itself was pretty and had all you need (big and comfortable bed, windows with the awesome view, hot clean shower and even fully equipped kitchen to store and prepare food if you wished.
Small things that could be improved:
Mariana was very friendly and replied every time, but slowly. Sometimes I needed fast reaction to get decisions, and responses were coming too late.
Check-in with key-boxes system can be confusing if not well explained. But in the end I was very happy with that system, as my flight was delayed and I could check-in at 2AM, in the middle of the night, which would bot be possible in any other place.
The floor in the apartment was not so tidy (the rest of the place was clean)
2 of the 4 lamps were not working (but other 2 were working and it was OK)
The automatic light in the corridor was banging on and off (with a sound) every 2 or 3 seconds. And when I came for a first time and needed to make that code for the 2nd door, I was quite frustrated with the light which went off all the time - it was hard to enter that code in the dark.
But, as I mentioned, those are only small details. The place is great and I would come back again and I'd recommend to any travelers looking for nice simple leaving.