You can trust the reviews. This is a great rooftop apartment in a relaxed and safe part of Valencia. Handy for the beach, local markets, restaurants etc and with easy transport links to anywhere in the city.
We stayed for a week and lived on the terrace. Sergio has some vinyl records you can play which is a nice touch or you can input your phone if your taste is more up to date.
There is a well stocked kitchen, large fridge etc - all you need.
No air conditioning but ceiling fans keep you well cool and as you normally have the glass door slid open when you are on the terrace then air conditioning wouldn't really work.
Sergio was on hand for our arrival and kept in touch throughout our visit.
As has been mentioned the stairs up are steep but the peace and quiet of the apartment rewards the effort.
If i was returning to Valencia, I wouldn't look anywhere else.