The wider base 45mm is much better....

I'd not get too hung up on materials .....thats only a flavour change rather than a design principle change.

This is meant as a low cost alternative to the stupid money "isolation" units that you can buy from some dealers.

As I've said under my cdp stillpoints with ceramic balls had exactly no effect nil nix none...

the 45mm dia oak with 8mm balls was a relevation....they also trounced RA's large and small oak cones ....

I've a selection of cones and feet including michel tenderfeet [large and small] vecteur cones and some chineses ones ....none have as much influence on the performance of my cdp as the the 45mm dia with the 8mm balls.