I didn't think the Iyonix actually used the acceleration the Geforce permits, so it's not going to get much of an advantage (not even using the alpha blending by the looks of the icon plotting figures).
A Kinetic can't use DMA for a Viewfinder, so it'll be dog slow (VF is slow enough without turning off DMA too!)
VARPC uses DirectView IIRC, so will inherently use the full speed the graphics card allows under Windows, but these graphics cards are heavily optimised for 16+ bits, so running Iyonix/VARPC in a 256 colour mode will slow it down, not speed it up (kinda the case with the VF too, except it has more data to shift across the Podule bus, so gets slowed down in the end).
I found that running fullscreen as opposed to windowed gives you a fair speed up with graphics, and a slight slow down with FS read/writes....
Can anyone run this on an Omega? I'd be interested in the memory timings compared to the Iyonix.