The appartment is situated at the edge of the historic city, next to Serranos towers and the park. You are just close to everything. You have a supermarket at 1min walking distance. And Metro stop around the corner (<5min walk) that brings you to the beach in 20min.
The appartment is very clean, spacious and well-equiped. You have everything you need for a great stay: a very comfy bed, airconditioning and a nice sunny terrace.
There is not much street noise, so you can easily sleep with the windows open (if airco all night is not your thing)
A taxi from train station to the appartment would cost you 8-9€ or you could do a 30min walk to the appartment. Pere even offered to arrange a taxi for us when we left the appartment (very convient if your spanish is not that fluent)
He also gave us many tips for things to do/see/eat/drink in Valencia. None of them were a disappointment. He is also very involved with his guests and responds quickly when you have any questions
Only disadvantage, there is no elevator in the building and you have to go up/down 4 floors. On the other hand, it is a good work out to work off all those delicious tapas.