Ernesto's place is very charming, located right in the heart of Valencia's historic El Carmen neighborhood in the shadow of Torres de Serranos. It's a beautiful apartment with all of the accommodations you would expect. Ernesto is a great guy, with excellent recommendations!
This is not a knock on Ernesto or the apartment, but something to be aware of for light sleepers: Because it is located in a rather busy and bustling neighborhood, I would recommend sleeping with the windows closed tightly and the AC fan on (the outside alley can get pretty noisy late at night, lots of late-night singers). You might also consider bringing earplugs if you're sensitive to noise while sleeping. The room in the rear of the apartment with the futon may be a good option for you as well, although I did not try it.
Overall I thought this place was fantastic and would recommend it to anyone looking for an adventurous stay in one of Spain's most beautiful and historic cities.