I traveled to Valencia to run the marathon on December 5th. Simon's apartment is conveniently located near the city centre as well as the Ciudad de Les Artes y Sciences (the start and finish for the marathon). However, the location is both a blessing and a curse. While the apartment is conveniently located it's also adjacent to a major road with an unbearable 24/7 traffic noise. Even though the apartment has new windows they do nothing to either prevent or mitigate the outside noise.
Heating
While heating is irrelevant for most of the year, it matters in the month of December. It's particularly chilly in the morning and evening and I had to find out that there is no heating in the apartment. The only way to increase the room temperature is by using the heating function of the only available A/C in the bedroom. In my opinion, it's insufficient to heat the entire apartment.
Utensils & Accessories
The kitchen is missing basic accessories such as a coffee machine, water kettle, toaster, and cooking utensils.
In conclusion, there are many apartment rental options in Valencia that are both cheaper and nicer. I'd only recommend this apartment for $70-$80/night. Otherwise, this apartment is seriously overpriced considering its shortcomings.