So it is a crap shoot each time
Seems to be that way. My test PC MoBo was a Gigabyte GA-7S748-l which has the SiS 748 chipset and the clients computer was MSI-6533 which is based on the SiS 650 chip set. The disk removed from the test PC was a WD Caviar 80GB with a fresh install of XP, SP1A and not much else. I was trying to verify the inetgrity of the clients hardware, it was a HD failure, but not in an obvious way (and thought I'd better be 100% sure before I started billing him for it

), and was a little surprised when all booted up with not a single windows error, as normally like you say it either won't boot, or goes crazy (in the case of 98). First time I saw the "...you must reactivate windows within 3 days...." message.....
Interesting about the RAID array. It can be a bit tricky to set-up those SATA disks. I remember the first time I stuck a SATA disk in one of my computers, and tried to install Windows.....took me a while before I figured out that I had to "press F6 to install a third party...... blah blah blah".....
cheers
EA