We had a wonderful stay at Alvaro's apartment. The flat feels new, is exactly as advertised in the pictures (it even felt a bit larger than what I expected) and it's nicely furnished. Checkin was easy and the location is amazing, near tons of great cafés and restaurants and walking distance to all major attractions (Casa Batllo, Sagrada Familia, Gothic neighbourhood, art museums).
Don't hesitate and book it. I know I'll definitely come back there next time.