Well, we did 33ml today, reasonably hilly so a lot of gear changing, on a tandem there's far more changing than on a solo, and the gear change was near perfect. One shift in the middle that required a further movement of the lever and one shift from 3-2 that ran onto 1 for a brief moment before settling on 2. So in the high hundreds of shifts only 2 were not perfect. That's around 99.9% I reckon.
What I did notice right from the start was how light the shifts were moving up the cassette, so much so that I shifted 2 at a time for the first few.
A relavation!
Paul H, yes I was aware of the Shiftmate zero but it doesn't do a 180deg bend as you point out. Prior to this I was thinking of using a shiftmate to convert to the long cable movemant of SRAM and using a SRAM mech.