Both themes have a stylish, elegant, modern and minimalistic look with a floating transparent menu with sliding tabs at the top of the browser. ECLIPSE has the mainmenu at the right side of the browser. Eclipse2 has the mainmenu at the left side within the container. This is an example.
ECLIPSE allows to create dynamic menus which move along with scrolling. Such menus will be always visible.
This theme has a splitmenu: the submenus appear in the sidebar left or right.
This is an example.

ECLIPSE has up to 8 ExtraContent areas that allows the user to add more content then RapidWeaver typically allows.
You can use this area for textlines, images, Google ads, a Date and Time snippet, text, images or whatever. Colours, font, fontsize, borders and background can be changed in the Colour Palette in the Theme Styles and with the Custom CSS Snippet. Below is an example of the EC5 area.
ExtraContent 8 can be used for slideshows on the header with one of the Image Slider plugins. You can import these with Pluskit in any other page.

There is an option for a Searchbox (you'll need the RapidSearch plugin for this) in the footer. This demosite shows some examples.