I have the Pertronix II module and 45K Coil in my 69' ZZ3 Coupe, and so far, I just love it. I'm able to open my plug gaps from .035 to .045 and they burn much cleaner. I've only had it for about 6 months, but I think it was well worth the $125 investment.
I'm so happy with it, I've installed the same set-up on my 70' 442 W-30.

I've had the unit in my 68 427 car now for about 18 mo. I love it, it seems the engine fires-up much more quickly and runs a little stronger.