I didn't see the point of HAML - until I used it. I'm a complete convert now: the syntax is just so superior to being productive in markup for me. In my current app I'm including a small ember app, having to write straight markup for handlebars (hamlbars is a bit awkward) is painful compared to how quickly you can produce markup with HAML.

Personal preference of course, but to me the difference is night and day in terms of my productivity with producing markup.