Well, according to official statistics, Barcelona lpayers run a 10% less ditance than the rest of teams in La Liga. That means our pressure is good because we know where to go and place people, not by sheer muscular prowness. That's what makes us great, the brains and skill. So don't try to put the drug shadow above us, please!
About the clash, I think Arsenal shoudl change their strategy. Walcott is a MUST against us, but also you need to play with very very narrow lines and double defend Messi and Xavi all the time, and hope fot the rest of the players to have a bad night.
Still, injuries may occur, and if we loose Messi or Xavi, I think we're no longer favorites anymore. It's closer than what people thinks and the first match at London will be very important for the outcome. Contrary to what people think, I predict a very close match at both stadiums.