We stayed in Sergi's Apartment for 2 weeks, it was HOME for us!! the place is cozy, spacious and very bright, we where a family of 4 and it was plenty of room, we even he'd some friends over for dinner and It was great!! the best part of the apartment? LOCATION LOCATION LOCATION!! you will be close to everything and in a very nice area of the city, 5 min walk to rambla de Catalunya (great restaurants there) and 7 min to Paseo de gracia, many stores and restaurants too.
I will recommend Sergi's apartment 100% this is place you will feel like a home away from home, it will make your vacation very special!