I made an article on my blog with testing Symplex's driver both in a stock 3.1 installation (with BetterWB from Gulliver) and in my current beefed ClassicWB Full installation.
http://mfilos.blogspot.com/2012/04/a600-picasso96-via-indivision-ecs.htmlYou can clearly see the differences in speed as Stock3.1 is really responsive and fast on 256 colors. ClassicWB with heavy patching and Scalos is a bit slower, as I believe 3.9 would be even more.
Also you can see the difference in speed comparing it to my current ClassicWB installation using Ratte's SuperPlus 800x600 driver @ 8 colors (MWB) which is really fast and nice.
Anywayz... Symplex's driver is still on progress, so I expect that further optimizations might occur. It's really neat by all means.

I'm gonna try other RTG tests like Novacoder's Boom and perhaps (for fun) AfAOS lol!