It was our own fault for not doing our research properly, but as with many areas which have a major rail terminus nearby, at nightime the environment changes.
First the good - the directions and communication from Manuela were excellent - we arrived very late (after midnight), and someone was there to meet us. We immediately felt at home in the apartment, and it is an excellent space when you have three boys (2 of them teenagers!). The welcome pack of food and coffee was amazing, and there was wine, beer, juice, milk too. We slept very well, as you can close the windows to the noise, and the air conditioning made it comfortable. The kids enjoyed watching the Netflix TV after days of walking! Location wise, it's very near the station, so getting around is easy. We felt very safe in the apartment, and there was generally someone on the gate downstairs keeping an eye on comings and goings.
The negative, which I hadn't really seen in the other reviews and I would like to have known (as I said, my fault for not researching) is as with all of these areas after dark the place feels a little different. There is certainly a 'red light' edge to the area, and I didn't like walking around with the kids after dark - so we got taxis, which worked out fine.
I don't want to sound negative, because the apartment is lovely and just what we were looking for. I'm just not sure I would have taken my children to such an area.