My wife and I had a fantastic time staying at Joaquin's place. He was very easy to deal and communicate with, and I wouldn't hesitate staying at one of his units again.
The unit is very well situated - just off of Gran Via (a couple blocks from Rocafort metro station). It's about a 5 minute walk to Placa Espanya and 10-15 minutes to Placa Catalunya. As it's just a bit removed from the major street, it's surprisingly quiet. Perhaps best of all it's in a more residential, less touristy area (yet you can quickly be in the heart of the action within minutes). Transit and restaurants are easily accessible.
The unit itself is very nice - large enough to accommodate a family or group of friends, and with all the amenities you could ask for. Just as shown in the pictures.
We would gladly stay here again!