Cagney??

I shoot anything from Ballet to punk rock gigs, whatever I'm requested[and of course paid to

] The latter being my preference, I shoot gigs just for fun at times. I don't present myself as a gig-photographer, just happens to be a lot of musicians around here, and I know a fair few of them. It's more the odd gig I do rather than regularly.
Lower fps? With an FX camera you are able to use fast enough shutter and balance the light out with higher ISO and still maintain a clean enough image.
The ISO performance of the 800 is superior to the D90 by far, I would imagine the D300s is similar performance-wise to that, as they used the same sensor.
When shooting gigs or shows, I never use flash. I mostly use my 24-70 2.8, and primes like the 35 1.4 and my 85 1.8. I also use my 150mm 2.8 for tighter shots since I sold on my 70-200. I try to keep the shutter speeds up as much as possible. 1/125 at least, to prevent blurring.
The ISO performance on the D800 allows good clear, non-noisey shots at 1/200, even stopped down a little for extra sharpness. Just a quick example, I don't post many job-shots online;
Brother Shabo & the Soul rebels by
Cagey75, on Flickr
Nikon D800E [EXIF].
Lens: 70.0-200.0 mm f/2.8
Exposure: 0.005 sec (1/200)
Aperture: f/4.0
ISO Speed: 2000
Focal Length: 200 mm