I had about a year of going back and forth on a 2011 or a 2013. At the end of the day I realized the 2013 had nothing I wanted.
Turn assist is cool, but for me to be in an area where I need to turn that hard, I'm probably in rocks and using my lockers. So I'd have to turn off my lockers, then unlock the center diff (which is on the second I hit dirt), then go into crawl control and activate turn assist. That's just more work in my opinion, plus I just can't get myself to trust crawl control in that tight of an area.
That's me though, I know how to wheel the old way (which isn't better, it's just what I know) with gearing, lockers, and awesome line selection. So the extra cost for a 2013 wasn't there.
Plus I hate cooled seats, there is no way I'm going to trust a camera on the trail when it gets rough to tell me where every obstacle is, I'm going to get out and check things, and the radar cruise control isn't for me.
Honestly, I wish I had the non upgraded 2008-2011 that didn't have DVD/navigation or the rainsensing windshield wipers or cool box.
I think if your plan is to keep it relatively stock, the 2013+ and the extra money that goes with them might be for you. If you plan on modifying, escpecially with lockers, then the extra money for a 2013+ can build a really nice 2008-2011.