Communication with Joaquin and Natalia was excellent, they're very flexible (we arrived a bit earlier than expected but it wasn't an issue for them) and gave us many recommendations for bars and restaurants.
The apartment is exactly as pictured and the location is perfect, very central. There's a bar next to the house and it's a bit noisy in the morning but not at all in the night. I would really recommend this apartment if you're visiting Sevilla.