|Re: Users have been using external RAIDs with the High Definition TiVos for two years|
There's a little more to this device than a simple external drive. They've removed the internal drive, and made the system external only (not that big a deal, really), but do keep in mind that there are 2 1TB drives in that enclosure, together with RAID 1 controller, power supply, and fan - probably about $275 worth of parts.
I've had a 750gb external on my series 3 for about a year and a half, and heard some clicking from a drive once, a few weeks ago. Having a replicated system would be nice. As it is, I'll probably have to replace both the internal and external drives, and be off line while I copy everything over. (I'll probably take the opportunity to increase the internal drive to 1tb or 1.5tb).