Spain played their most attractive football pre-Bosque when they had the Brazilian at DM instead of Buesquets and made better use of Cesc and his directness in combination with Villa and Torres playing as actual strikers.
Barca can play without a real striker because they have Messi and despite the ridiculous talent in their squad it is almost shocking how reliant they are on Messi to make things happen.
I think if Spain went back to basics a bit more, with one DM a couple of creative CMs(two of Xavi, Iniesta, Alonso, Cesc, Silva...etc) and got some direct pace out wide(instead of trying to fit all their playmakers in the team), they'd be far more efficient and exciting IMO.