Container Pro increases your layout options by providing a means to nest blocks in a container. As of Headway 3.1, the nesting of blocks using ContainerPro to avoid layout issues should no longer required. However, it does still provide other advantages that Headway cannot.
Firstly, it adds more design flexibility, allowing, for instance two blocks to have styling as if one.
For example, the navigation and header on this page are in a Container Pro block. This enabled me to align them together and still have the default block shadows and border to display the same as all other blocks on the page. Without Container Pro, it would not have been possible to get exactly the same appearance – although I could have got close, but you would have noticed still.
Or you might want two or three blocks but with one background image behind them.
Secondly, Container Pro also lets you embed a block within the flow of your content using a simple shortcode. Currently, the only limitation is the block must appear on the same page being viewed, ‘though any block will be supported soon. ( i.e. Besides mirrored blocks, it can’t pull blocks from other pages.) So, for instance, you could embed a Tabs+ block.
Note: Container Pro requires use of custom CSS to perfect layouts within the container and is therefore aimed at advanced users.