I decided not to wait for daVinci's modified SRAM RD and ordered the bits and pieces to convert from 9 to 10 speed: 2 chains (yes, I need two chains!), inexpensive Deore RD (I'll maybe shop used for a fancier RD), Jtek Shiftmate (Campy to Shimano) and 11-32 10 spd. cassette. The 10 spd. eliminates a few of the large jumps in the 9 spd which are bothersome since our cadences don't have a large overlap. Jetks are being pretty widely used so I'm not anticipating any issues. I should be done this am, but it's (heaven forbid) actually raining so might not get to road test today. Will post my impressions.

I noted in another thread that the Rohloff IGH has a constant 13.6% spacing. IGH looks very attractive for some applications, but my limited tandem experience says that unless the team are really well matched 13.6% seems like a big jump. I'm comfortable 87-100 and I would say my wife runs out of gas at 92 or so. I am working on leg strength which will help in the lower cadences when climbing.