I use PermissionsEX and Essentials. Any player with or without permissions can run the vault commands. The error message "You do not have permission to use that command!" is shown but then, in the case of /vault-info the information is still given and in case of /vault-convert the error message is given again but get the response "You must have at least 2 economies loaded to convert!" is given. I assume the command would function even if I had 2 economies loaded. I am not set OP on the server and have stripped myself of all permissions, even going so far as to include "-vault.*" to permissions. Using version 1.4.1-b436 of Vault.