Lack of fastram doesnt make it effectively a 7mhz '020, it simply shares mem bandwidth (which is slower than "fast" ram) between cpu and chipset, meaning it'll be saturated in most situations, leading to sub-optimal results.
SuperFX is probably weaker than a stock a1200, but not a lot. Starfox looks ok, but isnt fullscreen, and polygons are removed at the slightest whim to keep up framerates.
p.s. AMOS3d does indeed work on an a1200,... I just now checked.
