Users appreciate the Ozh' Admin Drop Down Menu plugin for its efficiency in transforming the admin menu into a horizontal bar, thereby saving screen real estate and improving accessibility. It is praised for making navigation easier, increasing productivity, and providing a more intuitive experience than the default vertical menu. Many users install it as the first plugin on new sites. However, drawbacks include the need for manual tweaks in the code, issues with ads cluttering the admin space, problems with menu items overlapping or not being fixed when scrolling, and difficulties managing numerous top bar tools. Overall, it's valued for its functionality but needs refinements for better user experience.