Nice images Brett.Thank you for all the feedback. I'm ok with a little noise; I got the photo attached tonight and it has been put through LR4 for lens profile and 30 NR. That one isn't too bad but the wiggle room for either less noise or more shutter/aperture would help.
I have no experience with the 5DIII. Among other things, I shoot live theater. I've been shooting pro bodies for a decade...typically keeping the previous body as backup to the new body. I'm currently using a 1DX with a 1DIV as backup. I've also held onto my 1DsIII because I shoot actor headshots and I wasn't sure if the IQ of the 1DX would be up to to the task (it is).
I've decided that I will purchase a 5DIII as a backup. It will be a little weird for me to shoot a normal sized camera again. It seems the AF and high ISO are similar to the 1DX and I would like a smaller body for travel.
Since acquiring the 1DX, I've settled into using 5000 ISO for live theater. I'm hoping the 5DIII will give me similar results. Here are a couple at 5000.
Its fun to shoot live theatre, I particularly like it when they turn out the lights and have just enough light so a person can see the action. That's where the 25600 ability comes in. Of course, most of the time, ISO 3200 or even less is fine, but when the lights go down, that's where the challenge is.
I'd get a 1D X, but haven't been able to justify the difference in price to myself. I had a 1D MK IV and used it to 12800 quite nicely, but went back to the smaller body to to carpal tunnel issues in both my hands.
The 5D MK III degrades gracefully at extreme ISO settings, so even though their is noise, it doesn't increase on a steep curve as the ISO goes up.