FWIW, my old 2013 600 still has the original QD belt. I sold this machine to a buddy, nice guy I am, gave him a new spare belt. We were going to change it this year and keep the original for a spare. But the belt still looks like new even though going into its 4th season.
If you are buying, get the 14 belt, but if you already have the 13 belt, ride and don't worry about it.