A few things. I own the Sonnet Tempt ATA/133...not the RAID card, but essentially identical.
The firmware upgrade, easily downloadable from Sonnettech.com, only runs from booting up in OS 9 (not Classic), but it's otherwise quick and painless and does work. I have a Quicksilver 933 and I'm running 3 WD 180GB drives in there, no problemo.
Enjoy!