I installed these drivers last night, and the IQ is even better than it was with the 3.4 based Omegas! I was VERY surprised, as IQ was already excellent! I'm using a Sapphire 8500 on this system, and this is definitely a good upgrade for the older cards!
This system also has Win98SE...(to be upgraded this week, hopefully!) The Win98 install has a definite problem! When running the driver, while "unpacking" it will stop and ask for "Disk #2", which of course, doesn't exist! At first I thought it was an incomplete D/L, so I did it again..no dice! I tried 2 other sites, same issue! There appears to be a corrupted or missing file.
There is a relatively simple workaround....install the stock ATi 3.5's, and don't bother with the Control Panel (you'll need to delete it before installing Omegas, so why bother?). Then install the Omegas...the same thing will happen. Cancel out of the installation, but note the location of the "unpacked" files under "Programs".
Go through Explorer to the Omega location, click "Install" again from the "unpacked" folder, and all will run normally! The missing file will already be in place from the stock ATi install, and seems to be untouched by Omega's optimizations.