I ordered a class legal Quantum main. You can find my reasons for getting dacron a page or two back, but it had nothing to do with class regs.
In the Seattle area, we don't bother with the main restriction when we race OD. I don't know all the boats, but most of the regular J30s only have laminate mains.
Me and my crew have only been racing about a year, so NAs would be a big trip we're not ready for. If we were at a point where we'd consider NAs, I'd say we wouldn't come if we didn't feel our main was competitive and we wouldn't buy a new sail just for one regatta.
I didn't answer the poll question about NAs, because currently sail material has no impact.