The Sega 32X may not have lived up to its hype but it did produce a few decent titles and Digital Foundry tested them all. Notably, John Linneman looked at the render split between the Mega Drive/Genesis and the 32X. As the description says, the results are often surprising.
(Featured image: Sega MegaDrive 32X et Mega-CD by Frédéric BISSON, shared via CC BY 2.0 licence; image cropped and rasterised)