I took Doug's advice and bought a Studio II 2TB Raid drive. No problems at all - dead quiet, works quickly with my MacBook Pro with Firewire 800 (DAC is Cosecant v. 2). It doesn't appear to have the build quality of the Caldigit (which became the main backup for my desktop), but the Caldigit is so noisy that it interferes with the music.
So thanks for all the advice I've gleaned from this forum. Really made my transition into computer audio a breeze.