Generally speaking, the apartment is nice; it's spacious, has a comfortable bed, and the bathroom and kitchen are well-equipped. A definite plus is the fact that a water filter is installed, so that you don't have to buy bottled water or deal with chlorinated water. The outdoor patio is also nice for breakfast (although the surroundings are not very nice). If you don't mind walking, you can get to most parts of the city within 15-45 minutes. The neighbourhood itself is not interesting, but very close to the riverbed park.
What bothered us, however, is that the airconditioning was not unlimited use. You get 1.5h per night for free, after which you can purchase additional time through a little box on the wall for €1 per 1.5h. I understand the reasoning (people leaving the A/C blasting when they are out, electricity being expensive etc), but this should have been mentioned in the listing. We do not deal with heat very well, and sleeping without A/C in the summer heat of Valencia was not an option for us. This means that we were paying an additional €5 per night in order to be able to sleep.
It would have been courteous if we were informed about this beforehand. I would recommend the apartment based on our comfortable stay, but just know that you will need many €1 coins if you require a cold room to sleep.