"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."

I don't think such a comparison exists. I don't know that any saw maker
offers the wheel material of your choice. A well designed saw with
aluminum wheels will out perform a poorly designed saw with cast iron
wheels. Toss in the variables of guide blocks, blade tensioning and setup,
you truly have to compare the entire package. FWIW, a cast iron base will
make it more stable than sheet metal, but you won't find them easily either.
--
Ed
http://pages.cthome.net/edhome/