>With matrix or >center-weighted metering I will usually get blown highligts >when spotlights are involved.
The little concert shoots I've done with spotlights I agree, I'd worry a lot more about blown highlights in spotlights than the focus. And of course shoot raw, then slightly blown can be brought back, and you may need that to get the background to have enough light.
You might want to set up for 3 shot bursts and grab a stop under and over. At 10fps there's not a lot of movement (not suggesting you use HDR, just that if lighting is tough this gives you choices in post). More shutter noise though.