"Brad" wrote in message
I know the weight of the cast iron helps reduce the vibration, but would
like some specific comparison like "my saw with alum wheels vibrated a lot
on this 10 inch piece of oak, but my saw with cast iron went thru it like
butter."

The one material advantage cast iron has is mass. More rotating momentum
makes cutting smoother (flywheel effect) by further reducing speed
fluctuations. Either material can be machined and balanced to perfection (or
not).

I'd look for a solid wheel (versus spoked) if you plan on lots of blade
tension (1" or wider)

-Bruce