Re: The issue is changing the password...
That is the usual argument for most data-at-rest encryption where you have a fixed random encryption value and your password simply protects that so a change of key is simple and fast as you don't have to decrypt and re-encrypt all of the data using the past and new keys.
But who would have assumed the same of a disk? I always assumed that your PC (e.g. BitLocker mentioned) would present some high entropy key to the disk and if you changed password that key would be unchanged, as would a software implementation of disk encryption. After all you don't really expect to have the SATA bus, etc, snooped upon during operations. If you do its kind of game over anyway...
Biting the hand that feeds IT
