the picasso II is better than nothing, but you have to realize that A2000's zorro 2 is really slow which is lucky to push maybe 2-3MB/s, couple that with only 2MB on board the Picasso II card and you suck most of that up when u run it up in the higer resolution. 800x600x16 is probabaly as good as it gets and it will not be speedy (well,better than ecs!).
The 030 and some fast ram will help the situation alot especially with 32bit ram.
Mech