Based on the specs, I'd say that it should work find under both 9 and X.
The tricky one for Mac OS 9 compatibility is that it has to be OHCI compatible for USB 1.1 (not UHCI), although later versions of X do support UHCI cards. I found that one out the hard way with the Via-based card in my Sawtooth.
The tricky one for Mac OS 9 compatibility is that it has to be OHCI compatible for USB 1.1 (not UHCI), although later versions of X do support UHCI cards. I found that one out the hard way with the Via-based card in my Sawtooth.