Ernesto's place was quite comfortable. It is spacious and there was good air-conditioning (which is a must during summer in Seville).
The hosts are friendly and approachable, and they were quick to respond to any problems that we had - when the water heater broke down, they were able to fix it within the next morning. When we mistakenly thought that the lock was spoilt, Ernesto was also very quick to help us (the lock was not spoilt; we just didn't turn the key hard enough).
The only downsides are that the place was a bit dusty when we arrived, and the lighting was a bit dim. Overall, still a good stay.