We spent three nights in Carlos appartment and it was a really nice experience. It is in a perfect location in historic Valencia with just a few minutes to all sights and restaurants. It is also rather close to the tram station for going to the beach (a 20 minute ride).
The appartment is bright and sunny with small balconies where you can watch people go by, a full kitchen and bathroom. There were some noice from closeby restaurants at night, but it is not a "party area" and it didn't disturb us.
We were two adults and two children and it worked well. The bed is good and the sofa bed is OK for a few nights.
Carlos was very helpful with arranging a parking place for us and quick to reply to questions.
We would recommend this appartment to others.