My boyfriend and I spent 3 nights in David & Lucia's apartment and it was a very positive experience! The apartment is small, but new and very nice: you have all you need for a long week end in Sevilla.
The apartment is 15 minutes walking from the cathedral and 2 minutes to Alameda De Hercules (the perfect place to eat some tapas and drink some cocktails). Lucia has been very nice and gave us some useful advice for our trip. They were also so kind to keep our luggage after checkout while we were spending last hours in this wonderful city.
I would definitely suggest you to choose this apartment for your next trip to sevilla!