My Drobo-owning friend found non-trivial problems with the Firewire interface that wasn't present on the USB interface. The symptoms were consistent with slow memory leaks. It ran for a while then slowly ground to a halt. After making a stink, they sent him a new one, with some hardware revs in it.

Meanwhile, two weeks ago, one of my two LaCie 2-disk striped RAID things stopped working. You'd hear one disk spin up while the other wouldn't. I did the LaCie tech support and they diagnosed that my external power supply had partly failed. They sent a new one, I swapped it in, and it's now magically working again.

What can I say: I'm impressed so far with LaCie.