I used this module for a while. It allows customer to surf through categories very well.
Vertical menu of categories is considered to be old fashion and now
the main part of e-commerce sites use horizontal, mainly
dropdown, menus. But good old vertical menus often are more
preferable, especially if the list of 1-st level categories is too
The addon Dynamic Categories gives a possibility to set a good looking
and convenient for using vertical menu. It opens dynamically the
subcategories of the active category and this makes navigation
visually easy. Beside this there is quite interesting option to assign
to each category an icon, this is easy to do in the the "Addons" tab
of a category. This makes the menu more attractive and more readable.