What's absolutely clear is that Edge and Bono should never do any promo on their own again. Full band is the only way to go (even if Adam's bass and Larry's tambourine couldn't be heard at all). Nothing beats the feeling of seeing the 4 guys of the greatest band on Earth playing together.
I haven't seen the performances on the Graham Norton Show, but it seems that these performances are getting better and better. Like Sergio said, it's the best band in the world. They're just trying to figure out the songs is all. Las Vegas 1997 compared to Mexico City 1997 lol
Acoustic is crowd pleasing. You don't get Bono prancing around with his stupid smug faces that people can't stand. As boring as it might be if you follow every single promo appearance, it works from a PR perspective.