I would suggest shaft drive, for one less job to keep on top of. Ntv are available not ratted - if fact better Google dispatch bikes, see what they use, but get one that's seen less miles. Any sports 600 that's 10 -15 years old or more seem to dump value. I used to get Used bike guide to get the concencus on if somethings a lemon. Less of an issue these days I geuss, mainstream manufacturers have done hopefully most of their learning. Famous last words.