Generators and await don't really give anything substantial after promises except less superficially verbose syntax and not even that when using CoffeeScript where `return` and `function(){}` are really light-weight. Actually what issues generators and await solve are same as what CoffeeScript "solves".

Although with generators you "can use normal control flow constructs". Except in most cases you probably use map or forEach instead of loops anyway. And try-catch is really broken.