The Amazoness Quartet and friends come off no worse than the antagonists in the other Sailor Moon series. In fact, most would say they fare better. At least they benefit from a clever plot twist that makes then senshi in their own right. Plotwise, the SuperS manga is tightly choreographed. There are no filler stories as in the anime.
Every page is critical, every occurrence with purpose.
Most of the material is unique to the manga, but those scenes that are shared are almost invariably the ones that were the most loved in the anime. The age-switching of Usagi and Chibiusa is particularly notable. If you loved it animated, you'll love it twice as much in the manga, where it is handled more evenly and with much more poignance. It is worth noting that many of the popular scenes from the animated Stars series were in fact borrowed from the SuperS manga. All these similarities aside, it is the plot elements that are unique to the SuperS manga that make it truly worthwhile.