actually K2 was pretty sneaky about the 11-12, and 12-13 model. Same graphics, but they actually added tweekends to the 12-13 model. The flex profile is a bit different. I had both and put up comparison pics at splitboard.com. The sneaky part was that K2 told some shops that they could just sell the 11-12's as 12-13's. Also, talking to k2 customer support about a splitboard is like trying to talk to my mom about splitboard parts. Whatever, it's a great board. I just had the option to upgrade to an ultra split but turned it down.
The way to check what year your board is, is to look at the serial number (on the right edge near the back binding holes. If it starts with a 12 then you have a 12-13 with tweekends