We had a great time in Valencia in Carolina's apartment. It is very funky, clean and well equipped with everything you need. We thought it was located out if the centre but everything is within walking distance and the local area of Rustasa has lots of bars and places to eat.
Our only problem was with the people in the flat upstairs. Not sure if this is a regular problem but they came back late 2 nights in a row over a weekend and we're talking loudly, playing music and dragging chairs across the floor. There doesn't seem to be much sound proofing between the two!
Apart from that would totally recommend the flat as somewhere to stay.