I have been following this thread with interest for a while, and thought it would be fun to contribute. I have a basic Leica slide projector sitting in my closet, with a Leica Colorplan 90/2.5 projector lens (which replaced the rather average Hector 85/2.8 lens). The following shots were taken along side my Tokina 90/2.5 macro, with the same focal length and max aperture I thought it would be interesting to see how they compare.
All pictures taken with my D600 from a tripod. The Colorplan was "mounted" via a set of K extension rings - the tubes simply allowed me to hold the projector lens by hand while keeping it reasonably well centered and blocking stray light. Focusing was achieved by moving the lens in and out to achieve a sharp image.
First up, the trunk of a tree aloe, covered with dead leaves which have remained attached to the tree. Tokina first, Colorplan next. The Colorplan has a slightly narrower field of field of view so the focal length may be closer to 95mm. The central sharpness is excellent, nearly as good as the Tokina, dropping off towards the edges of the frame. The Tokina is known as the "Bokina" as it has a reputation for good bokeh but I don't think it holds up at medium-far distances, the Colorplan has much smoother background rendition (none of the funky bokeh featured earlier in this thread)