The weak link is Adam Clayton, aka Mr. 8th Note, but he does all he needs to do. Root notes and keeping time. Larry Mullen is easily the most underrated dude in the bunch. Very good drummer with his own style much like Edge. Bono is a great frontman with a unique and soaring voice, at least in his heyday. The Edge used delay like nobody before him. It was as much a part of his instrument as the actual notes coming from it. He found his own thing and executed it beautifully. I think a lot of people are just pissed they didn't think of it before him. It gave him the ability to fill space that he otherwise couldn't fill, and to blend rhythm, lead, and atmospherics into one guitar, something that usually requires two. Look at the difference between something early like I Will Follow, with its four notes total (2 for each section), and contrast that with something like New Year's Day a few years later, which really was the first song to really signal his future direction. Unforgettable Fire and Joshua Tree had a little bit of Eno and Lanois to help, but even contemporary live renditions of the songs from those albums show that the studio versions are not just studio trickery.