Pro Designs generally are less complicated to set up and maintain, and they are in most cases typical *Blog* Designs. Their content is almost 100% comprised of blog posts, and very rarely do they include advanced options like Portfolio pages or advanced Visual Effects.
Premium Designs usually are image-heavy, and have advanced options regarding layout, color and content presentation. Most of them contain at least one distinct Portfolio layout, some of them have many different Portfolio or Gallery components. The content can be presented in many different ways, almost always accompanied by advanced Visual Effects.
Ultimate Designs are just that – Ultimate. The possibilities are virtually endless — from variable layout and color options, stunning Visual Effects and interactive elements that can be switched on and off for every single page. They require the most time to set up and maintain and are only suggested for sites with an abundance of content.