It's first time I'm spending that much time to write a review...
I've rented the place for nine nights. Would I recommend it? Depends on what you are looking for. From my perspective suitable for 1-2 nights for a single traveler (especially first time visitor) who is resistant to the noice, has a good budget and doesn't need much sleep.
POSITIVE:
Communication: Outstanding, both Marta and Marco are super responsive and deal with requests in a very professional way. Usually in less than half an hour.
Location: Very central, you can find good restaurants and nice shops in a walking distance.
OTHER DETAILS:
Price/Quality: It's not an apartment, rather a room within a bigger unit. You will not have much more space than in a hotel room, but you will have a small kitchenette with all essentials. The price was quite high due to a high demand at the time I've stayed. But on the other hand a friend of mine rented a place during the same time period with four times as much space, beautiful kitchen and high quality design. It was located in 5 minutes walking distance and she only payed 10EUR more per night... So it might be worth to invest more time in research.
Noice: It is very loud, especially in the evenings and weekend nights.
The entrance door to the room is just a simple door and doesn't help with the noice reduction at all. And the room is located directly at the entrance of the apartment which means if your neighbors come, go, talk... you hear everything. I didn't sleep for three nights because of this.
And add all the noice from the street on top as the window is practically not isolated and it is a very lively location.
Cleanliness: Generally ok, I was offered a cleaning service in the middle of my stay.