^ Adam's bass line is perfect on that song. It, along with Edge's short solo and Bono's vocals, really makes the song what it is. A lot of times when listening to MOS, I really get lost in just listening to and focusing in on that bass line. With how well the song is layered musically, it's easy to get lost in just one aspect of it.
And I agree, I think it might also be the amount of time that hurts them the most. There gets to be a point where you can't change/revise the song anymore without decreasing the quality of it. I think U2 understands this, but on some songs have clearly given into the temptation to continue working on something that would be better left alone.
Agreed about Pop and Zooropa. It's funny because up until maybe 3-4 weeks ago, I hadn't really heard either album. Since the first listen of each, both have been in near constant rotation in my CD player. They're fantastic CDs in their own right.
It would be awesome if U2 does something different from here on out. Maybe doing something ambitious like releasing a new CD every year for the next 4-5 years? I'm sure they've got a ton of inspiration to draw from. And if they're like most procrastinators/pressure workers, they'll thrive on the tight time window for each CD, much like they seemed to have done with Pop and Zooropa.