Two of my friends and I visited Seville for the marathon. Daniel's apt was perfect - large enough for all of us (in fact it can easily fit a family of 5 or 6), well equipped and well located. The old town is undoubtedly the best place to stay in this beautiful town.
Daniel is one of the sweetest hosts I've ever met, eager to assist its guests. He went out of his way to assist us with airport transportation and was super easy to communicate with (in a town where English won't get you far...) . When I take the family to Seville, this will be the place I'll return to.