I feel so bad for Bono; I have a bad back myself, so I know how painful it can be. I love U2, but I wasn't going to see them this year anyway.
As far as Christina goes, there has been some speculation that she washed up & sales for her concerts aren't going so good. When she tours next year, it'll be at smaller venues. I don't know if I personally would ever go to see her live. She's alright though, & I don't think she's washed up, JMO.
Wouldn't go see the Eagles, etc. either. Not too into country music.
Lee