Not impressed at all.
The apartment is so-so. The cleanliness was not the best. The pictures were somewhat misleading. There is much more wear and tear than depicted. There were also some electrical issues in one bedroom by the street, missing latch on the sliding glass door, and some other minor issues here and there.
But the worst part was the noise. We stayed for six nights, and almost left after the second. The noise the first two nights was unbearable. There was a group of guests literally having a party above us (we recorded the girls singing Justin Bieber's "Baby, baby, baby," and a few other tunes. I reported it to Sweet Inn and they said they told me the guests had been told to be quiet. Maybe they didn't get the message. Nothing changed.
So they gave me the phone number of the security guard. I sent him a message, and he rang our doorbell at 1:30 AM... 1:30 AM asking to know what was going on. I don't speak Spanish very well, and he didn't speak English at all, but the noise was so loud we had a difficult time communicating -- me from my 1st floor balcony in my t-shirt and shorts. I know this is Spain and all, and they're more into the night life (and it was Saturday night), but seriously?
The remaining nights, the noise was more tolerable, but decisively noisy. Peculiarly, the elevator shaft runs through the middle of the apartment. When you get out, you exit directly in the living room. There is no insulation whatsoever in the elevator shafts making conversations in the apartments above and below as clear as if the guests were down the hallway.
I asked my teenage kids what rating they would give and they both said, "Two." I asked why, and they said that the WiFi never really worked, and the rooms were small. I didn't consider that a defect, as I'm used to hotel Wi-Fi never working well due to bandwidth and all. But it was an issue for them.