We had a fantastic stay at Ivaylo's place. His colleague let us in and we just left the keys behind when we left.
It's a newly refurbished flat that's light, airy and clean. Lots of space - we went as a family of four but would be plenty of room for another couple. It's in a great location close to the marina, a short walk to the beach and close to the tram to easily get into central Valencia. There isn't any info in the apartment so pick up maps/online recommendations and tram details beforehand.
There's a kitchen with oven, hob, fridge and freezer as well as dishwasher and washing machine. There's all the basics for preparing food (as well as oil/salt/pepper etc) but you might find more extensive cooking difficult.
There's air conditioning in the main bedroom and living area but even though it was hot weather we rarely needed it. There are shutters on most of the windows which are great at blocking out the light - particularly when travelling with children so we weren't up with the sun! The kids loved the bucket and spades that were there - fantastic that we didn't have to buy some just for the week!
Would recommend if you're planning a trip to Valencia!