Ok, will I also be able to run a campy wheel (ya know in case I want a
pair of fancy campy race wheels) with this on? It so this seems the
answer.

Thanks
Emory

I recently converted to 10sp Ergo with Campy rear derailleur and
Ultegra 9sp cassette and have had NO shifting issues. It works better
than the all Shimano set-up I had before. People seem to have
different experiences with this so you may or may not not find the
Shiftmate to be necessary. I would try it first without it.

If you did install one, I assume you could still put on a Campy wheel
sometimes, but it would then be the odd man out wrt cog spacing and
may not be "perfect". It's not really practical to pop the shiftmate
on and off because it requires an extra loop of cable.