If my memory serves me correct, this is Button's tenth season in F1, which is more than most ever do, to my mind without ever xactly thrashing his team-mate?
This year he had a car which was aerodynamically leaps ahead of enyone elses due to a loophole in the regs. Together with the best engine, the results were only to xpect if you ask me. Competition has now caught up and on a track such as Suzuka they were midfield, also to xpect from a comparatively small team.