Alex is a great & seasoned host: responsive, hands-on, patient, gave a lot of useful tips, and is very knowledgeable about all the common and less-known sites of Barcelona. You can ask him anything.
We were only two using the apartment, but I can see how it can easily fit 6 people. The space is bright, clean, spacious, quiet, cozy, complete amenities, and kid friendly.
Location is great! It's far enough from the touristy areas to feel safe from pickpockets, but close to the metro line which connects to ALL the tourist attractions. Nearby is a cute park with a playground, affordable markets, groceries, and the like.
I highly recommend this place, and I def. would go back.