“Bring the vibe”, V Festival’s nebulous marketing slogan, was heard and heeded on the opening day of the two-venue rock-pop shindig. Said vibe was present in the form of this year’s festival drug, nitrous oxide – canisters crunched underfoot everywhere – and in groups of lads who cheered on Example, the uber-lad, but were less sure about Justin Timberlake, the headline act.