Personally I don't get the interest vaulting with a private company who have practically no transparency vs vaulting with a public company (like a bank) who have reporting requirements and reasonably open books.
Is the fear that legislation one day treats asset seizure differently depending on whether or not the vault is managed/owned by a bank? If so, what factors are going into that risk analysis?
The vault at BankSA King William Street in Adelaide is quite impressive.