I'd stay far away from Lacie drives of the bigger capacities, unless they've reworked them. I've got one from 3-4 years ago, a 500gig. It's really just two 250gig HDD's in a RAID 0 format, which is incredibly unreliable. If one fails even just a tiny bit, the whole thing is fucked!
HDD capacities are much higher these days, though, so the 500gig LaCies should be a single HDD.