The apartment is ok, clean and everything worked. The neighbours can be a bit loud and tend to listen to music late at night but it's bearable. You will get a good phone reception, because there is a huge communications tower on the next building.
The immediate neigbourhood however is one of the worst in Valencia, but dont worry, the locals from the neigbouring ghetto (across the street) are mostly fine, they won't hurt you, because they are preoccupied by their own miserable lives when having a frenzy by the nearby trash bin (15 meters from the property) or just minding their regular business as drug addicts and dealers. I've never seen more desperate people trying to find a dealer in the middle of the night or more people getting searched by police from head to toe.
There is a liquor store under the building frequented by local thugs and junkies, they are occasionally shouting and threaten the life of the owner but hey, that's just how things are around here, nothing special. The city does a pretty good job clearing the mess by the trash bin every dawn and the police does a good job controlling the thugs (during the day at least, because they seem to be sleeping at night - when most of the action is happening - just like everybody else).