@Hyperspeed
the main benefits of planar modes show up in screens with few colors. For a screen with 4 colors, in planar mode you gain a lot of memory and speed. Planar was used long before the Amiga, the very first Macintosh (monocrome) used it. When OCS was designed, it could display at most 32 colors, so planar was absolutely the best choice. For 256 or more colors, apart from the ability to scroll separately the individual plane (which is good for special scrolltext-like effects but not much else), I would say planar has no benefit, but many disadvantages (apart from the aforementioned ones in the 3D, also for 2D BOBS chunky is better).
I don't think PCs have always used chunky: before VGA, there was CGA and other gfx standard with very few colors: I don't think those were chunky. Also, I have heard that old VGA board used to have a 16-color planar mode. Maybe it was part of the VGA standard and it's still there in the VGA boards... it would be interesting to know!!
my 2 cents
