Ants!
Bad: Ants throughout apartment, including bedroom. Host brought Raid, which did not help. Was told not to use kitchen counter due to ants. Perhaps not a problem in colder months, or perhaps common in Spain - but I was surprised to find ants on the 2 floor of a building. No one could come in to solve issue due to holiday in Seville followed by weekend. Electricity also went out while we were using several appliances - resolved quickly but something to be aware of.
Good: Great location! Very quiet, seconds aways from city life. Friendly host (Joaqin), came back several time to help with issues (replace iron, bring Raid). Arranged taxi for us to go to airport very early during the day. Had useful suggestions for tourists.