Y'know it's funny - when the first leaked Quake builds got "into the wild" and people were compiling/converting the game for the Amiga, I seem to recall the framerates that people were reporting - 320x200 @ 8-10fps, that sort of thing, and describing it as eminently playable (a fact that I found just astounding considering the standards most PC gamers put on FPS's, even back then).
One man's slideshow is another's gaming dream, I reckon.
EDIT:
Lest anyone think I'm slagging off the Amiga, I'm not - I mean, there's platform games on the PC that "look" just fine to me yet don't move as smoothly as some for the Ami circa '88, so I know there's different kinds of parity.