I'm split on the manner as a whole.
On one hand, you have people like the person in charge of U2gigs who takes pride and is loved by many for the massive amount of good quality video he took of the 360 tour. He helped me and plenty of other U2 fans experience the thrills of a new debuting song or just a good performance who weren't able to get to the show, which is really nice. Its something I even took for granted at one point.
This same fact goes for those who try to take professional, or really quality photos during the tour. I commend them for doing so, and probably have various photos as backgrounds on my computer.
On the flip side, you have those who try at every moment possible to take a photo or video of the band. Half the time, they spend the concert staring through a video screen in order to get an average at best picture, or a low quality video. Now I can't hate on all these people, because sometimes you might want to get a few pics, or a video or 2 (I took one of Zooropa, since I figured it would be a once in a lifetime thing), but sometimes you just need to put the phone down to really enjoy the music. I especially hate those who take pictures and videos solely to prove they were there, although this doesn't happen too often (hopefully).
In reality, U2 is such a massive act where it would be hardpressed to get fans to not record video or take pictures. If they wanted to, I suppose they could acknowledge it once during the show or something, but in a way which doesn't degrade the ones taking the photos and videos.
But all in all, I can't say take photos or videos really takes away from the enjoyment of a show. I think the real matter is how much and the effort given into getting the video and/or picture. If your glued to trying to get a perfect video, you probably aren't enjoying the show as much as you could if you put the device away.
Sometimes the best way is to get lost in the music itself.