Wheeler puts ESB at 35 and Pride at 30. Of course we don't know how Fullers calculates theirs!This resulted in a bitterness of 42.55 (the normal ESB target is 34).
http://rarebeerclub.beveragebistro.com/rbcbeer_12.html
Chiswick seems less hoppy to me than ESB mentally I always pegged it at around 27 but that is probably light for a bitter.