I find HAML mostly just replaces Rails tag helpers.

instead of:

<%= tag "div", {:id => "city", :data => {:name => "Boise", :rating => "good"}} %>

I can do

#city{:data => {:name => "Boise", :rating => "good"}}

Which is basically the same thing. All haml does is encourage using a taghelper like syntax for everything.