If this is the class -
http://www.sewingexpo.com/Events/Atl...0/Default.aspx - it's only 1.5 hours long, and that's not long enough to learn and practice very much. The class at the LQS sounds much better to me, and then you can go to the Expo just to look around.
Craftsy also has classes on ruler work for DSMs. You might check them out.