There are many advantages in renting a vacation apartment over a hotel room. You have the independence of coming and going as you please - like a real resident of the city you're visiting, and also have the added advantage of having your own living room and kitchen, which is such an added bonus if travelling with children. Even if you're travelling in a group, the financial benefits can easily outweigh gettng 4 or 5 hotel rooms.
BCN Rentals has some great apartments for rent in Barcelona, and specialises in group bookings and family get togethers. See some visual images here:
The professional staff are always on hand - just like a hotel consierge - to help with restaurant reccomendations or bookings, theatre tickets and book taxis or transfers. BCN Rentals also has a strong partnership with a reputable taxi and minibus firm, and almost always organise collection from Barcelona, Girona or Reus airport. The site also includes a fantastic Barcelona Guide with details of the major hotspots you will want to visit whilst staying in your Central Barcelona Apartment.