What FDE (with hardware encrypted drives) for OS X works?

FWIW PGPDisk works ok on Mac OSX in my experience, had it running on a MacBook Pro with Leopard without any major issues (although I wasn't doing much in the way of heavy development with it, so hard to guage the performance hit)

WinMagic is the only one I know that even claims to support hardware encryption, and they claim to be the only one to support Seagate Momentus drives. The Sophos/Utimaco and PGP products don't support hardware-encrypted drives, and TrueCrypt can't encrypt the boot volume.

By the way, I worked on implementing one of the FDE products listed above, and while I'm no longer associated with that company I would still advise that FDE is a better choice than FileVault. Without getting too nerdy on the details, FileVault has a kernel-userspace communication that acts as a measurable bottleneck and even causes deadlocks in some heavy-use situations. Also, it clearly doesn't protect data written outside the home folder, e.g. to the default temp location in /var/folders. Conversely, the FDE software encryption is typically all done block-at-a-time inside a kernel extension, and the vendors know that they'll get destroyed in reviews if it slows anything down :-)

As described in Apple's marketing blurb, there will be built-in full disk encryption in OS X version 10.7.

PGP's WDE (Whole Disk Encryption) works pretty well. Its worth noting that you can use a drive encrypted with PGP WDE as a local Time Machine backup drive, allowing a fully encrypted continuous backup solution. Note - use a complex password to encrypt the drive, NOT a key.