I very really use a templating (theme builder WordPress) system to create my WordPress themes. On the odd occasion I have used both Headway themes and Ithemes Builder. Both are great WordPress theme builders. They certainly both lighten the load when it comes to design time. So there are some real positives and also some negative in using both WordPress theme builders and I will go into some detail now on what I mean.
Ithemes Builder - http://ithemes.com/purchase/builder-theme/
The great thing about Builder is that it allows you to build fantastic layouts for any number of pages. It allows you to be able to use child themes (they currently has 60+ child themes) to build on the default installation of builder, with the help of a style manager and obviously the layout manager in Builder.
HEADWAY THEMES - http://headwaythemes.com/
The great thing about Headway themes is the simple and easy to use Drap and Drop system to create layouts for your blog or website. It definitely speeds up the web design process. Basically you can draw your layout with your mouse.
There is no decisive winner in this. They are both great WordPress frameworks and I would recommend that you check out both.
If you want full control over anything you design, then the best way to do it, is to design the theme from scratch.