Mmmm not sure but it would be an interesting contest.
In the red corner we have a 7MHZ 68000 with a chunky 8bit display....and in the blue corner we have a 14MHZ 68020 with a planar 8bit display....ok, FIGHT!

The Graffiti was a device that when I first saw an advert for one in AmigaFormat (12 years ago?), I remember being a bit confused as to how it could work... So I sat down with a pen an paper and try to work through the idea... and once I had figured it out, I realised that it was probably the most brilliant idea ever

As I understand it, the Amiga sets up a 1 bitplane bitmap, and then the graffiti treats every 8 (actually I believe it was less than this) pixels as bits in a single chunky pixel.
If my understanding is correct, then for an 8bit chunky display, the maximum width would be 160 pixels with the graffiti (with either 256 or 512 pixels high). Unless the device can just treat the whole Amiga output as a single bitmap? Then we have 1280*512 bits = 81.9Kb, and if an 8bit 320*256 display is also 81.9kb... that would be a very acceptable lowres 8bit chunky display on an ECS machine!