The flat generally is fine, the location is good, too. Keep in mind that the bedroom doesn't have any window (not clearly mentioned in the text). Some rooms (kitchen, bathroom) smell a bit strange. It's a little bit sketchy that there's a bunch of people involved in the rental, every response in the chat is from a different person and the check in is still done by someone else unrelated...
HOWEVER: We had severe water damage from (apparently) the flat above in the bathroom, from the 3rd day on (out of 7). It drizzled from the ceiling, became more intense and after a few days not only did the water cause electricity short circuits (no lights) but it was also literally raining from the ceiling so we had to sit on the toilet with an umbrella (sounds funny, it isn't.)
The treatment of the problem and communication was slow at first and not resolved. After complaining more, sending more proof material, and having a very wet bathroom for a few days it got (temporarily) fixed. I'm still giving 3 *** because we received a 20% refund after communicating our massive disappointment and having long discussions.
It's always easy to say "it's an old flat, these things happen, be happy about the location, or just leave if you have a problem with it" (which was what they said), for a highly professional Airbnb agency with 30 (!) flats in Valencia (according to their own information) this is not acceptable in my opinion.
Maybe we were just unlucky, although they said it was a problem before already with the water from above.