I have both, love both.
If you can afford new, do it.
If not you can save a few grand on a gen 1.
If you buy used, try to do research on the prior owner or buy from someone you know took care of it.
Buying used should not be an impulse, take your time and find a good deal.
I prefer new when buying high performance motorcycle's due to the nature of the abuse they can be subjected to.
I know people that I would not buy a used ball bearing from. (they could tear anything up)
Most of the my past purchases have been used bike's. When buying used it would take me a long time to find the right bike at the right price.
PM me if you need more info between the gen 1 and gen 2.