Tiger will do fine.
As far as your shaft drive concern, if you dig deeper you may find a number of DNF's due to the shaft failing. When that happens your DONE. if the chain breaks it is possible to carry a spare and replace it rather quickly. I would certainly prefer a chain drive over shaft any day.
Have you done the "voltage fix" for the Tiger?
Carry an extra stator as well if you are concerned.
Check this guys blog, he is an Inmate here as well, I think he has a few miles under his belt on the Tiger.