The Cobra is similar to the SL from what I've read, with a different shape.
I believe, and Snowolf will comment on this, that his feedback with the Heritage specifically (or indirectly) led to the Cobra shape. Which has a spade tail for great powder performance. It was the one thing he didn't think was great about the Heritage (powder).
That's odd... because this is what I got back from Never Summer in an email
Originally Posted by Never Summer
The Heritage is going to be similar to a slightly stiffer and more aggressive version of the SL. It is an all-mountain board in our Carbonium lineup and can handle any type of terrain. The Cobra is going to be similar to the Proto CT with some characteristics of the all-mountain boards. It is a slightly setback directional board with blunted tip/tail and sidecuts like the Proto. You can think of it as a mix between an all-mountain board and a stiff park board. With that being said, you may like the Heritage if you are looking for something to ride mostly in the powder and big mountain areas!