I had a wonderful stay in Valencia at Solana's apartment. The apartment is a nice size for single travellers or a couple. It is nicely decorated and well-fitted out - as well as exceptionally clean.
In terms of location - its smack bang in the middle of the old town. The roads in the centre of the old town get very narrow and windy making it easy to get lost. My uber driver gave up after circling the place for 15 minutes and dropped me 100m away from the front door. The flat is up 3 flights of steep stairs with no elevator.
There is a very good Italian restaurant on the corner which is very convenient. The patrons can be quite loud but the restaurant closes at 1am-ish. If you're in Valencia for the night life this isn't a problem.
Solana was a fantastic host, providing lots of useful information as well as tea, coffee, milk and bread as well as snacks.
I'd definitely recommend the apartment to friends visiting Valencia as the central location is amazing - nothing quite like coming downstairs and being surrounded by the city!