The Amiga has 4096 available colors which is a plus, but the color palette is only 32 entries. So your options are 1) one background layer with up to 5 bitplanes = 32 colors, 2) one background layer with 6 bitplanes and 64 colors, with the additional 32 colors being half the intensity of the original palette (called ExtraHalfBright mode), 3) one background layer with 6 bitplanes where each pixel can be one of 16 colors OR it can have one of the R/G/B components given with the other two being copied from the previous pixel (called HoldAndModify mode), 4) two seperate background layers with up to 3 bitplanes (8 colors) each (called dual-playfield).I think I have seen Amiga compared favorably to the PCE and MD, particularly for being able to display three actual background layers simultaneously. Also, the colors and capability for MOD players seems to leave the PCE or MD behind if I am not mistaken by too many exaggerated comments on the topic. From what I have seen of the Amiga 1000 I would be shocked to see a version of R-Type not surpass the PCE/TG16 game.
The Agnus chip can step through a list of register changes to make on certain scanlines (called the Copper list) so mid-screen palette changes and other raster effects were pretty common since they don't necessarily take up any CPU time. I forget whether Copper takes any CPU memory bandwidth, but 5- and 6-bitplane screen modes do steal some bandwidth which slows the CPU down a bit.
Also, there are only 8 sprites, 16 pixels wide, but they can be as tall as the entire screen. So again, the copper list could be used to break-up one tall sprite into multiple smaller sprites by changing sprite registers during the display, but it takes CPU time to figure this stuff out, whereas it's done in hardware on other systems.
Sample playback is much better than PCE or MD but there are only 4 channels. To get more would mean software mixing which is demanding on a 7MHz 68000 so this is somewhat limiting.
My numbers are from the 3Dmark2001 fillrate and high-polygon-count tests. I have a 6GB HDD with Win98 installed on it that I had swapped into various machines. Changing video cards was no problem once I had found the right drivers. Changing motherboards would need an extra reboot or two for everything to sort itself out. Although in one case I ran a couple of benchmarks on a PCI 486 board and since the BIOS was so old it required modifying the partition table to match the different representation of the drive geometry. Then I had to change it back afterward so the drive was bootable on the newer motherboards.Which benchmarks did you use for these figures? I'm waiting for a PCI ATA 133 adapter to come in and then I can test all of these cards too. Also, do you have a best practice for swapping video cards? I remember crashing Win98SE by upgrading once, I am very worried that I won't be able to swap these cards today without reinstalling the OS.