Thats why I have a '15...
The mechanical systems should be identical. The only difference is the interior and exterior. IMO the interior of the 15 was significantly nicer than than of the earlier models - in particular the navigation/backup camera is standard. And most of all no red interior gauges! Let BMW keep its red interior. It seems as though there is added sound dampening, but I didn't drive an early trail with stock tires, so it's hard to tell between the two on that issue.
I do tend to like the exterior of the earlier models a bit better.
For me there was just no reason to buy a 4yr old used 40-60k mile 4runner when I could buy new with warranty and unmolested for less than $5k more. On the bright side - the high cost used one still sell and the resale should be excellent sometime down the road.