To be fair to him, he mailed back an hour or so later to say both drives would be replaced.
Then, this morning, working from home, I got a call from the loading bay manager at Reading saying a Citylink package had arrived for me. Oi vey. So much for my RAID-5-tastic weekend.
Oh well, guess I'll just reassemble a PC around the XP3000 instead and set it up with XP Media Centre Edition which, I hope, is arriving here today and not Reading.