A few months ago, I bought the full-frame Canon 5D as a back-up and have since embraced obscenely wide shots; my 16-35mm rarely comes off of the 5D during concerts now, and it’s normally stuck on the 16mm side.
The top five things I’ve learned as I’ve been working more and more with my wide angle:
1. The best shots are when the band comes to the edge of the stage. Despite this being true for concert shots in general, the closer the subject is to the lens, the more impact that shot has.