I'll go with Botha, sure he's well past his best but who has Sonny Bill fought? BTW Williams gets KTFO by Parker
I voted Botha by ko, but to be honest I wouldn't be surprised if he showed up out of shape and disinterested, in which case a tko or a wide decision wouldn't surprise me.
When Botha steps on the scales of truth 24 hours out it will become clearer how serious or otherwise he is taking this fight.