With things like Haml and Coffeescript, the only truth is that YMMV. On the individual level, I do think you can find actual objective gains in developer produ

With things like Haml and Coffeescript, the only truth is that YMMV. On the individual level, I do think you can find actual objective gains in developer productivity, but on a aggregate level, it becomes muddier because of the variation of developer habits. Personally, I eliminated a lot of problems associated with close tags in my markup by using Haml. But my coding habits aren't someone else's coding habits, so Haml (or Coffeescript) can go from being a solution to being a problem for someone else.