I've never said it was technicaly advanced or harmonicaly advanced, but in terms of melody and musicianship and tone it is flawless and no one else can make their guitar sound like that. end of story. In terms of effects, there's not much going on besides distortion and slight delay, maybe a little compression sustain at the end. Whenever people say," its just fx bla bla bla..." about anything the edge does, i have to just laugh at them. Maybe you'd like his solo in this song, starting at 1:46 :
First, I'll say that was the best I've ever heard from The Edge. I've never been impressed by his playing. Again, it's mainly effects that allows him to sound the way he does. In the above link, the effects and sheer volume allowed him to get that sound. Nothing he did in there was advanced. Just by listening to it, I can hear him playing a minor pentatonic scale, and he repeated the same idea (motif if you will) a couple of times. Usually you do this to build tension, but I think due to the style of the song and genre, it doesn't go anywhere. Then, when he "releases" the tension, he's just doing a pedal tone by using an open string and playing the scale again. Nothing harmonically advanced.
Just like Stevie Ray Vaughan, nothing he did was ground breaking in terms of harmonics or chords he played over. Just the sheer feeling, power and the way he consistently (accurately to boot) put his ideas (and if you listen closely you'll hear his playing of licks is "limited" but how he strung them together endlessly) together is what is so impressive.
In this day and age, it's hard to do something that hasn't been done. What hasn't been done? We're in a time, where we've seen Coltrane, Hendrix, Clapton, EVH, Yngwie, Bach, and hundreds of thousands of other innovators. Where do we go next?