The 13 also comes with the retro mirror, back up camera, power passenger seat, and both seats lift. not just the my link, I got one with the dual mode exhaust also. And I do not regret changing from my 2011 vert at all, as I got the color and options I allways wanted. And it has the suspension modded also in the rear to make the toe links and trailing arms outside the shocks I think also on the 13.
I would go for the 2013 and the 2014 I think will have very few if any changes being the last year of the gen 5 if SEMA is any indication from the chevy performance booth other than maybe some optional badging and maybe a green color for the zl1 vert badged touring