I found the Ultimate's buttons were real similar to the ones you get with Faucetwo if you pick the default cheaper ones. Actually prefer the size and shape of the Ultimate controller. One of these days I'm going to transplant Faucetwo guts into it. Already gave it Sanwas which did help.
Yup. Direct swap, was simple to swap in Sanwas I already had spare. It looks like the bolt pattern for the knobs is the same too, but I've not actually measured.