Hi Lynn,
The horizontal menu on DNN C is the Solpart menu. The reason for using it is that was the only option I was aware of at the time.
Pros - easy to setup
Cons - Doesn't display in IE5 or if Javascript is disabled, lots of code created etc etc.
I am working on a new skin for DNN C which will use CSS menus and will probably make use of the sub-menu horizontal images menu that is demonstrated in the tutorial and possibly also combined with the vertical menu for any sub-sub menus.
Pros - Search engine friendly, works in all browsers, small amount of code created, therefore faster page load times
Cons - A bit more setting up required initially when creating the skins.
For any new sites I generally opt for CSS based designs. - Take a look at
www.skinningtoolkit.com which makes use of the sub-menu functions that are explained in the horizontal tutorial, but placed within a vertical menu. The menu consists of 2 HouseMenus which are styled to appear as one menu.
Thanks,
Lee