The appartment is in a great position for all you want to do in Bilbao, it's needed to clean much more then now and refresh the air and it's perfect.
Jon ospitality and attention to every detail for the confort of the client is perfect. I think he must to use the same attention to the appartment an all will be perfect.
For example the bed sheets are very worn and the shower is not so clean as you aspected, but it's all little problems that Jon can resolve in a few time.
If Jon resolve that problems the appartment will be perfect place to stay.