Regarding Native Son: I'm not so sure it was a mistake to re-work that. I was just listening to it again and really, the lyrics of Native Son are just too weirdly phrased to really fit the beat of the song. However, I think changing it to Vertigo was a step too far. Some sort of compromise probably would have been better than to sort of "dumb" it down the way it was, although I do really like Vertigo.
Not surprisingly, Lillywhite was behind that change.
However, I think Xanax and Wine should have been kept as it was. Again, I like Fast Cars (or at least the version on the Artificial Horizon CD) but the original is superior. More of a raw sound, slightly changed lyrics and vocally, it's better, imo. Another one is the alternate version of "Sometimes You Can't Make It On Your Own." A less polished, but better version of that song in many ways.
That's an interesting point about Pop, and it makes a lot of sense. What's a shame is the damage that Pop seemed to have had on U2 (and still has today, I think). The CD itself is solid and even great in some areas. But because it wasn't the smash hit and as beloved as Achtung and JT, it felt like a failure to them. Still does, I think. It's made them more cautious about every new CD they make and consequently, it's resulted in a lot of changes to the music that haven't all been positive.
Like I said, I hope they can get out of that mentality and realize that they don't have to overwork things.