Prohibitively early? I don't call getting there a few hours early prohibitively. Had to do the same thing for many other concerts that I've been to. If you want to be close, that just comes with the territory.
As for the claw and the sound--I did the GA and the seated thing at two different concerts. I never had an issue with the view (it was always good, though I'm sure there may have been a few spots in the stadium where it wasn't good) and the sound, where I was, was always good. I haven't been to any other U2 tours, so I don't know how 360 compares, but my experience was good. And I'm the first to complain if it's not good.
Regarding the pay $$$$$$ for a decent seat comment, yeah, that's how it is at a lot of concerts. It goes back to the scalpers and their buying up all of the good seats. I've seen it happen with the Chili Peppers, Coldplay, and a bunch of others. Tickets going for 2-3 times face value. It's why I hate seats and prefer GA because I know that I'll get a good spot so long as I get there a little early. I'm pissed that so many bands seem to be getting rid of the pit in favor of seats where only the richest fans have the chance to get close to the stage.
I don't deny that U2 want to make money. Of course they do. Most artists are that way. But what I do deny is that they're unlike all of the other bands out there. And they would not be playing stadiums if they could not get them 3/4 or even 2/3 full.