David was an excellent host - he always responded very promptly and all arrangements were made with the minimum of fuss and maximum of help and flexibility.
The flat was wonderful - clean, stylish, with a really comfortable bed. The kitchen was well equipped with everything you might need although with so many great tapas bars and restaurants around we hardly cooked at all!
We went to visit our daughter who was living 2 mins away at Plaza de Cascorro. She said it was a great area and she wasn't wrong. The flat is very close to 1 metro station (La Latina) and easily close enough to 2 others giving you a choice of lines. But even without that within a 20 minute walk of the flat lies most of central Madrid.
On Sundays the Rastro open-air flea market (though selling lots of new items too) is practically at the front door. Plenty of local bars and restaurants to choose from easily at hand.
Just be aware - the flat is on the 3rd floor, so you have to get used to stairs (seemed further after a few riojas).
All in all we were extremely pleased to be staying in David's flat and would totally recommend it.