I absolutely recommend Mery’s place in order to visit Valencia. It is not in the center but there is a metro close by and with a taxi it is only 15 mins or less.
Mery and her mother are FANTASTIC hosts, super nice and friendly. The apartment is gorgeous and the stay includes the use of a common garden which is also fabulous. I would totally suggest to stay here for a few days and enjoy it.
If I come back I would definitely come here and would suggest it to friends.