We've just received an EMC 3700 as part of an overall revamping of our infrastructure. From what I've seen so far, it's a great system. But it is seriously large bucks and only part of a plan to secure high availability. Any good raid system with hot swappable drives can give reasonably constant access to data 95+ percent of the time. As things get closer to 100%, the costs seem to get exponentially steeper. A disk subsystem alone can't provide high availability, the whole picture must include telecommunications (i.e. sonet ring), network, server and UPS failover alternatives. Are you looking for a hardened site, or simply a large, dependable disk farm? IMO look to EMC or HDS for the former, and the IBM or perhaps DG's CLARiiON for the later.