EPL is more aggressive and physical, but less mature tactically so being creative in EPL is easier. Hardly anyone can park bus there and teams, who immediately bullrush anyone, who gets the ball actually make themselves more vulnerable against playmakers like Cesc or Silva. Even likes of Bojan bosses his Stoke, because it's full of aggressive lumberjacks and coal miners, who play their football after their day job shift.
And although he maybe should talk less, Cesc is 100% spot on. Messi creates 3/4 of all goals for Barca. Without him it would be mid table team by now. And yes, Chelsea have changed their style quite drastically. I don't think current Barca would dominate them in possession if they met in CL.