After +10 years of running around with Canon 1D's I have lately found myself using Fujis more and more for concert photography with the reasons being:
+ quicker access to social media
+ less too carry = easier to move around in the photo-pit
+ live-preview of wildly changing white balance is quite nifty
- focus, still not good enough
- live-preview not quick enough if you are in the middle of a mosh-pit...arms/legs/crowdsurfers may suddenly be a lot closer than they appear
- fragile compared to 1D + L-lenses
Examples - so far so good...will be interesting to see how they cope with the outdoor summer festivals the coming months: