Alvaro's place in Barcelona was great for a quick 2 day stay! It's in Ei'Xample so extremely central to all the places in the heart of Barcelona. It's 10 minute walk to Sagrada Familia, 20 min walk to Plaza de'Catalunya, and 3 min walk to the subway.
The apartment itself is very modern and clean, with a private terrace. There's no elevator so be mindful if you have a lot of luggage. There's also a $4 euro/day per guest fee.
You can leave your luggage in the lobby that's securely monitored, and they were accommodating for early check in. Would stay again!