Is the Shiftmate still available? I thought I heard that the manufacturer gave up, or maybe died? In any case, some people loved it because you could swap it in or out, and it worked.

When I bought my Campy Chorus 10sp bike 10 years ago, I asked at the shop if I could use my Shimano/Velomax wheels. The answer was no, at least not if you wanted perfect shifting after dropping $3400 on the bike. Why kluge up an expensive bike? I did try them at some point, but as I already posted it didn't work well. As for Campy spacing on a Shimano/SRAM splined freehub and cassette, the inner limit is very tight and the two systems start at a different point. We're talking millimeter fractions here but it is surprising at what a difference they can make. Wheel dish usually has to be a little different.

I took the plunge into Campy and my only regret is that the replacement parts are so expensive. OTOH, I broke the right brifter in a crash and was able to get it re-assembled by Branford Cycles (are they still around too?). Try doing that with Shimano.

Will these combos work? Sure. Will they work flawlessly? Nope.

One type of shifting though that works a lot better than you'd think is friction shifting with the 10sp (or even 11) cassettes. With the ramps that are built into the cogs on modern cassettes, friction shifting is silent and effortless. Spacing is tighter too. A small touch of the shifter is all it usually needs, the chain will ride on the ramp to the next cog, or even skip multiple cogs, and land centered. There isn't any slop like in the old days of 5 or 6 speed, so no clanking of the chain between gears. It really works well.