Just came back from BCN and I couldn't be happier with my accommodations. Located in the L'eixample area of BCN, a quick subway trip (4 stops) will put you right into the center of town. Speaking of subway stops, The Poble Sec stop is less than a 3 minute walk from the apartment.
The apartment is located right on the edge of a little city square, in a nice residential area. A grocery store is located right around from the apartment and it is nicely stocked with anything and everything you may need for your stay. We were 2 couples and the 2 bedroom/2bath layout of the apartment worked out perfectly for us. The rooms are small and storage space is at a premium, so you will most likely have to leave your luggage out in the living room. 1 restroom, tight but nicely appointed is an en-suite off of the bedroom with a balcony. The 2nd restroom is a little bigger and is right outside of the 2nd bedroom. The small but cozy kitchen is well appointed, although if you plan on cooking you will have to buy most of your condiments because the apartment does not stock those items. To round out the apartment, there is a dinning table that comfortably seats 4 and a living room with a pull out couch, coffee table, tv and wifi router.
One of the great things about this neighborhood is the proximity of great dining options within a short (5-10 minute walk) down to Career de Parlamant. The street is filled with great dinning options. Also of note, a terrific gelato spot, on the same street called Artic-o and a Catalan ice cream shop called Sirvent, 2 blocks past Artic-O. Apparently some of the best "Spain" Horchata you will ever taste. Keep in mind, if you are familiar with Mexican Horchata, it is nothing like it.
The host was very responsive and always available via What'sApp. Unless you have a worldwide data plan on your phone, I would suggest down loading What'sApp before you arrive, because it is probably the easiest way to communicate in Spain, since most places offer free wifi.
Have a great time in this Spainsh jewel of a city and make sure you use this apartment as your home base. When I come back to BCN, I will first check to see if this space is available again.
Enjoy.