The internal system is ligther overall (including the boom) than a normal external system.

The boom is a normal section in weight, you could go smaller and lighter but then you would be forced to use an external system and thus be heavier overall.

Super Taipan is currently an external system until I make an all carbon internal boom <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />