it has many improvements,  many minor bugs have been fixed in this build, studiopress is releasing its updates of this parent theme according to the algorithm updates, to make it a more Search engine friendly framework. in this edition, this theme is more lightweight and more responsive, & compatibility for all browsers has been added. Genesis 2.5 has its focus on the organization, integrity, and testability of code, along with other improvements for broad compatibility.
13 Reasons why you should Choose the Genesis WordPress Framework : 

Get the most out of your site’s SEO.
Leverage the Synthesis hosting platform for amazing performance.
Updating keeps security locked down.
Has its own Commenting System.
Advertising widgets.
Want to extend a site’s functionality even more? Genesis makes it easy.
Sidebars, headers, and footers, in any configuration.
Featured image capability.
Take the worry out of updating to new versions of WordPress
Run and update multiple sites.
you’re getting access to the whole WordPress kitchen sink.
The benefits of HTML5 code.
You’re not limited to Genesis Plugins.
Child themes give you access to beautiful, responsive designs, but you’ll need a developer who knows CSS, PHP, and Genesis Hooks to customize them.

http://www.thetechex.net/genesis-framework-free-download.html