If you're a rubyist (in heart), you'd absolutely, completely hate HTML and something like this (a clean, beautiful syntax) is like Christmas present. And if write your client-side scripts in CoffeeScript anyway, then there's really no learning curve.
If you're looking for a templating language with clean, beautiful syntax, the question is why you wouldn't use something like HAML or Jade. They don't have the advantage of already being written in a familiar syntax, but they are easy to pick up, and they're well-supported and generally accepted by the Ruby/Node community rather than being an abandoned year-old code dump.
Honestly I prefer embedded ruby and rails helpers plus JavaScript and HTML where appropriate.
To me ruby's terseness makes sense as its an independent language, but something like coffeescript as well as haml and the OP's thing just feel like extra baggage and an arbitrary abstraction.
