I think he peaked in 2009. He looked nuts at the 09 O. I saw some comparison shots a while back from 01 vs 09 and in 09 he was just as shredded and bigger, and his legs were in proportion with each other.
There's a good argument for this, but in 2001 he looked fresher and rounder, with a smaller looking waist, less bloat, and his forearms haven't receded/atrophied yet. His Back, while wide, never had great detail. Even in 2009, he had wrinkled skin in his lower back.