I guess an asterisk is to consider what the card will be used for. This goes on a Nubus graphics card tangent, on the grounds of do you really need this considering recent discussion of what Nubus cards now cost on Fleabay.
For Marathon or Pathways Into Darkness, 1152x870 at 24 bit is not going to feel better than 640x480 at 256 colors or 16 bit color. The overhead of having a 68k derived CPU try to blit a subset of that larger byte buffer before it hits the display is going to slow things down, you're going to want to play at 640x480 at most for real time action games on any 68k machine.
PrecisionColor cards were really made for Photoshop, Canvas, FreeHand 4 and other graphic design apps that could throw more panels on screen when they had the the extra screen real estate. Being budget minded, those tasks can be handled about as well with a cheap PowerPC Mac for less than the cost of an eBay Nubus card.
But if you found this thing free in a Mac II, by all means go for it. Might even be cheaper than trying to source VRAM for internal graphics in some cases.