If DaveSSS is correct the J-TEC ShiftMates don't actually work, as they don't compensate for the pull per click difference, just the difference in average pull.

I'm eager to hear from anyone who has tried this.

Dave, from previous statements you've made it sounds like you've measured the cable pull for the Campy shifter yourself. Did you also measure the pull for the SRAM shifter yourself? If not please cite your source.