Sid's apartment is a fine place if you're looking to drop off your bags and explore the city only to crash during the few hours that Barcelona sleeps.
PLEASE NOTE TWO THINGS: 1) that this property is listed incorrectly and is nearer the Eixample neighborhood which is north of the current map listing. As previous guests have noted, Sid has you meet at a closer location before proceeding to the actual apartment itself. 2) the listing title is slightly confusing as the terrace is not apart of the studio (the house rules and not the general listing do clearly state that it's only available at certain hours) but is located on the other half of the flat.
The apartment lends itself to great sites, easy access to metro lines as well as Las Rambles, and is a great base location for seeing this city.