We travelled to Valencia with our 10 month old, and loved it! Julia's apartment is in a great location for getting the balance between time near the beach and in the local neighborhood, plus just a quick tram ride into town.
People have commented on the noise from the trams, so to reassure that while you do hear them (as well as the neighbours - to be expected with city living!), it wasn't loud enough to wake any of us, including the baby.
Comfortable beds, excellent communication, and everything that we needed for a short stay. Found the list of recommendations really helpful, and generally agree with all the recommendations, especially those in the local area.
Our only disappointing day was the trip to La Albufera, where all the restaurants felt a bit like overpriced tourist traps. I'd stick to the local area or Russafa for good food!