Umm you'll probably get better performance if you can find a Radius PrecisionColor/PrecisionColorPro/LeMans (LeMans is the best), or a Radius/RasterOps Thunder IV. These cards have good 68K drivers.
The significance of the MacPicasso is that they're the only cards for Nubus PPC Macs with 3D acceleration. Still, the AV/HPV cards of Nubus PPC (33/40Mhz clocks vs. 10Mhz in Nubus) are faster than any Nubus Video Cards for 2D performance.