So... Filevault sucks. Really. With PowerPC machines stuck on Leopard though, it's the only thing resembling disk encryption that we have, which explains why I have it enabled at all. If you're thinking about using Filevault, first move all your photos, movies, and iTunes library outside of your home folder. They don't need to be encrypted and Filevault sucks hard enough that you don't really want more in it than you have to. For moving the iTunes library specifically, just move it out of your home folder to its' new location before turning on Filevault, then option-click iTunes in the Dock, it'll ask you to select an iTunes Library, select your library at its' new location, and you're done. Then you may switch on Filevault. Anyway, my observations of it are that it sucks. It doesn't encrypt anything outside your home folder, including system logs, temporary files, etc. In system crashes, kernel panics, and power outings, you often get corrupted or lost preference files (bittorrent software like Transmission can really get hit hard.) The Finder doesn't remember what application you set to open which type of file (there's a workaround, Google it.) It's a royal pain the ass to have to constantly type in a long, secure password every time you want to change a system setting, install something, or unlock the screen. Time Machine becomes much less regularly used since it only backs up the home folder upon logout. Not one of those criticisms I listed was a problem when using PGP Whole Disk Encryption on an Intel Mac running Leopard or Snow Leopard. PGP Desktop 9-10 = highly recommended. Performance issues with Filevault: nothing noticed under general use, probably because most of my files have been moved out of my Filevault-protected home folder. It's about 6GB in total. I also make use of a 100GB encrypted disk image stored outside of my home folder. I did the AJA System test disk performance test on both sections of my hard disk to get some hard numbers, though, and it was quite a shock. Normal performance (no FV or outside of home folder) Read: 96MB/sec Write: 43MB/sec Filevault performance (tested I/O speed inside of home folder) Read: 13MB/sec Write: 22MB/sec This is on a dual 1.8GHz G5 with a new 7,200 rpm hard disk with 40% free space. The exact test I used was the "Disk Read/Write" test with a file size of 2.0GB and a "Video Frame Size" of 1920x1080 8-bit. "Disable file system cache" was checked, as default.