When extreme high ISO is better than nothing: a rundown on my experiences shooting ballet

You asked for user input. In my photography business, I shoot a lot of ballet and jazz dance. My two K-5 bodies each have 100K+ exposures in less than two years. My practice is to use something wide on one and long on the other.

Studio or Dress Rehearsals: DA12-24/4 and DA 17-70/4 or Tamron 28-752.8

Performances: DA*50-135/2.8 and Sigma 100-300/4 on loose ball head and tripod.

In most theaters, 50mm will barely cover the entire proscenium so 135 is a good zoom range. If I hadn't gotten one of the last new Sigma 100-300/4, I'd have a Pentax 60-250.

Most stages average EV 7 or 8 so I start at f4, ISO 3,200 and 1/320. Depending on the lighting cues and costumes, I'll go up or down a stop or two with ISO. I do not worry about ISO 6,400 or even 12,800. Occasionally, I've shot 25,600. While I may have to vary my Camera Raw defaults and use Noiseware sometimes, I don't understand the problem with high iso. I've taken stuff practically out of camera at 12,800 and been juried into very competitive exhibits. I print 11"x14" a lot and 16"x24" often. Attached are a couple of examples at ISO 6400 or higher but there are lots more on my event hosting site.

I haven't used anything but manual mode in years and only shoot DNGs. Stage lighting, especially the newer led lights play hell with DLSR sensors. Turn the blue and purple saturation in Camera Raw way down.

Regardless of camera brand I'd shoot the same way. As you discovered, its good to know the choreography, lighting, music and dancers.  Learning that has been why my work improves.

Besides my portrait business and dance, I shoot events for a local online publication. I haven't had any problems getting the shot with my gear. I'm sure the other stuff is fine equipment and if I had a need and couldn't do it with what I've got, I'd buy it. Last years gear budget and this years gear budget is almost all lighting. Haven't bought a lens or a body in two years.