I was told by other designers and developers that the ideal WordPress site design platform for both professionals is Genesis. It’s not as complex as Thesis, without much of a learning curve. At least for basic use. It’s different in that the framework sits separate from the site theme your are using. The analogy is that WordPress is the engine, the Genesis framework is the body, and the theme used is the skin or paint job.
For basic customization is easy to do, with the options of naming, color, logo images. For more in depth changes, you need to edit your theme functions.php and style.css only. Much simpler than creating a new files for each area needing changes and add to those. The term “hooks” is used since you pick one item from your site and place in a different place, or overwrite the place with custom functionality, like a new copy write instead of Genesis.