Valencia is definitely worth a visit, at least for a few days or even weeks.
A very good option for accommodation is Gabriela's apartment. It is located just outside the Ciutat Vella in a late 19th century building, with good access to the old town on foot or to the rest of the city and beaches by public transport.
The bright apartment is tastefully renovated, well equipped and has beautiful views of the surrounding area. The only challenge is the steep and narrow staircase to the top floor, but on the other hand it can be considered a daily exercise.
Gabriella and her husband Eddy were very sympathetic and helpful.
A warm recommendation.