Ya han dicho en diversas ocasiones alguno de ellos o colaboradores directos como por ejemplo Willie Williams, que ellos consideran que la duración máxima de los conciertos sin que se resienta el espectáculo es de 2 horas y cuarto. Al menos en grandes giras de interiores y estadios.

-------------------------------------------------------------
"We hope that they (U2) realize that radio is unlikely to put any song they ever write into heavy rotation; instead, they should just focus on making another great record, and then hit the road on an arena tour that drops some of the old warhorses in favor of great songs from the past. [...] We fear their primary focus is competing with Lady Gaga on the radio. It's a fight they're going to lose. Hey Bono, don't overthink this next record. Just make it great. It'll serve you better in the long run."
Rolling Stone (US), January 2012.