Science awaits, then! I've just completed my tests this evening.
I can't offer any wisdom on your driver choices; I'll just run through my adventure with the card this week. My system is an Aptiva 2196, which is a low profile SS7 system with K6-2/533 and SiS540 chipset (packing SiS300 onboard graphics). My focus was initially Win98 only. I've tried an MX440 in it, which brought nothing to the table (as I understand it, it's a bit out-of-era for useful driver support). I got my Rage XL this week and grabbed the following drivers:
Phil's ATI uploads (the Rage Pro and Rage 128 packs): https://www.philscomputerlab.com/ati-9x-driver-archive.html
This big Catalyst archive: http://vogonsdrivers.com/getfile.php?fileid=1 … 9&menustate=6,1
Not one installer recognised the card. The eventual solution was to let Win98 install the standard VGA driver for it on startup, then manually update the driver from Device Manager and navigate to either of the Phil downloads. (I tried both and saw no difference between them).
Rage II XL: 966
Following some discussions elsewhere I then got into some DOS testing with Phil's benchmark pack: https://www.philscomputerlab.com/phils-ultima … se-project.html
I also ran Keen 4 for a scroll test, and while the SiS was a bit juddery, the Rage XL was a mess of shaking and tearing. So none of my results paint the Rage in a good light, but I've got it up against the SiS and my real takeaway from all of this is that the SiS540 delivers some pretty decent onboard graphics. On the other hand you're starting with a Cirrus that probably slays my system for 2D stuff, and with the addition of some ATI 3D the only way is up, right? I'll be interested to hear how you go.
 I also tried the XL in this board, where it didn't work at all: http://www.win3x.org/uh19/motherboard/show/5956