Sorry I don't have a new Hitachi but it's nice to hear you are evaluating software solutions right now.
When I get myself a new 500 GB SATA drive I might take a look at CompuSec:
http://www.ce-infosys.com/english/downloads/free_compusec/index.htmlThere are a lot of solutions available (CompuSec, Safeguard Easy, Securedoc, Safeboot, Drivecrypt) but I have no idea which one does work with eCS and it's LVM.
I would still prefer a hardware based solution like the eNova stuff (e.g. W-Wall MX which is using AES) because it's totally software independent and the encryption/decryption is done in hardware which doesn't slow down the computer.