I installed the Hyperion 5.24a pack on XP last night on my KT333+VT8235 ECS K7VTA3 v6 setup. The drivers for PCI-ISA bridge, AGP bridge and IDE installed fine on their own. Ran some quick tests. I have a SSD on a PATA adapter and it's still getting 92-96MB/s sequential read which seems like saturated UDMA6. AGP is still running 4x, with sidebanding enabled, and no fast write support with the GF4 Ti and a run of 3DMark2001 went fine.
Might be interesting to run the Tom2D benchmark to see if anything changes in GUI acceleration between AGP drivers.
I also had a ASUS K7V-T KX133 + Athlon 1000 running with the stock XP drivers last week and it seemed solid. Even AGP 4x seemed to be working ok which is not supposed to be the case with KX133. In 98SE I had been seeing glitches and instability seemingly caused by the GPU, but didn't run into anything in XP. I even played some UT2003 on there.