Last time I saw Arctic Monkeys (before Sunday just gone) was Reading in 2009. On that occasion, The Prodigy who were on before them blew them away.
On Sunday, at Leeds, Bring Me The Horizon absolutely blew them away. Have to say that BMTH's set was one of the best, if not the best festival set I have ever seen.
Perhaps the problem with AMs at festivals is that better live acts are subs...