I use a portable external drive as my master disk. When I purchased a MacBook Air, I needed to change from a firewire to a USB-powered drive. My Aegis 160 GB drive by Capricorn lasted about 2 months and then failed to boot. I reformatted the drive and reloaded recovered files from backups thinking that I may have accidently disconnected it while transferring files. After another month, it failed again. I am fairly certain I did not accidently disconnect the drive this time. My portable firewire drive from LaCie lasted more than two years without problems. Needless to say, I am not giving the drive another chance.
