It's an interesting debate for sure and if most of your work invloves situations where it is most likely to be an issue, it makes sense to avoid it.

I recently shot a stage production where there were quite a few camera flashes going off at various times in the audience but I haven't seen any instances of RS in the footage yet (from capture). However, as I progress through editing, who knows what I might find. More of an issue for me is balancing the sound from the different performances for editing in from different angles (that's the main problem with "live" performances - no multiple takes possible other than from multiple performances. Can be a real PITA when you don't have total control over the sound and lighting as well. Obviously, it's all controlled by the backstage crew, so even when you take a sound feed from their mixer - it can still fluctuate as they tweak it for their purposes (at the end of the day, they are trying to produce the best for their stage performance - not for your recording of the event!).

If I do any more of these, I think I'm going to have to invest in a seperate field recorder for audio (as I recall someone suggesting on here some time back) :-)

The field recored might be a good idea. Of course with plays, they're usually all over the stage, so I wonder how much a single recorder will benefit you. But at the very least, it will be better audio than what your camera can achieve.

I think a 4 channel recorder would cover it reasonably well - with the option that one could also add a mixer into the equation. I think I could have covered the stage reasonably well with 4 mics. One area that's difficult to cover though, is continuity - the actors tend not to give exactly the same performance from one night to the next - or hit the same spots on stage! Still, it makes for an interesting editing experience! ;-)

It would be great to be able to mic up each individual but it's not really practical with a cast of a dozen or so. However, it could still be an option for those actors that I know don't have very powerful voices that need gaining up in post. It could introduce problems of matching ambience though...

I have taken an extra camera, hooked up a wireless receiver to it and placed the mic front and center near the stage and it worked beautifully, at least for a play. No sync issue, which I hate. I have a zoom h2 but don't use it.