It really depends on a lot of factors. In general, the difference will be noticeable only under certain conditions. A Quake benchmark on a low-res screenmode will be identical on both systems. Scroll through a large picture that exceeds the amount of VRAM on your gfx board (=swapping data over the zorro bus) and the 4000 will perform a little better.
Identical to the 4000.
It depends on the software. Quake is limited by cpu, not by bus bandwitch. In contrast Doom should show some performance differences as it's not so cpu heavy. Try out Voxel test included with WarpOS on an A2000 RTG and later on an A4000 RTG and you'll see the huge difference. AGA has more bandwitch than ZorroII cards for these kind of games.
