I am not a fan of these clubs. but they are, undoubtedly, big clubs. Real is a car for victories, and Barcelona is a creative and beauty of soccer, in my understanding. therefore now my sympathies on side of Barcelona.
both clubs have very strong children's schools, their pupils play across the whole Europe. but nevertheless I will write also about a negative. both clubs take away a big share from the television rights, lobby financial restrictions for other clubs (themselves don't limit as we see on their transfers) that reduces the competition and they will always be in 1/16 Champions Leagues.