I stopped using CS because it's going to have some issues when ES6 becomes more of a real thing. For instance, how is CS going to handle for/of loops when ES6 has it's own for/of loops that is slightly different. The same goes for class and super.
There will have to be CS2 that introduces new semantics and old apps will have to be migrated.
There will have to be CS2 that introduces new semantics and old apps will have to be migrated.