Until today, FileVault was the ugly stepsister of the Mac OS X operating system. Nobody liked it and anybody with serious security concerns used other disk encryption options. I would have given it a different name since FileVault was such slug. Regardless, Mac OS X now ships with some real security teeth. It includes whole disk encryption, Time Machine disk encryption, remote wipe of your Mac, and sandboxing. So long PGP.
The last time I used FileVault it broke everything, but a few weeks ago my paranoia took hold and I turned it on in Lion. I didn’t talk about it in my review much because I honestly haven’t spent that much time with it. It is vastly improved from when I last used it.
To date I have seen no issues and no performance problems — I am quite impressed.