Skimmer Filters are often times used in conjunction with regular filtration systems and waterfall filters. They are both functional, and beautiful to look at, providing additional filtration and aeration as well, by breaking the water surface to allow for oxygen to be absorbed into the water.
Skimmer Filters should be located on the opposite end of the pond from any Waterfall filter you may be using to insure for the best possible water circulation.
Skimmer Filters are best used for mechanical filtration, since the media they use assists in keeping the pond surface clean and free of debris.
A key point to take into consideration is the size of your pump, to insure adequate waterflow through the Skimmer Filter.