The Danforth, or Fluke anchor, remains a very popular anchor choice. The Fortress is also a popular Fluke style anchor, different from the Danforth in that it comes apart and it constructed of light-weight, high-strength, aluminum.
The Fluke performs well in mud and sand, potentially the best of any anchor style. The downside is that outside of these bottoms, it is not a good performer. Therefore, it is a mud/sand only anchor, which fortunately is what most bottoms are comprised of.
Whether or not it is used as a primary anchor, a Fluke anchor makes an excellent choice as a secondary or stern anchor.
Pros: Performs well in mud and sand. Stows easily on most bow rollers.
Cons: Does not perform well outside of mud/sand.
Bottoms: Top performer in mud/sand. Performs poorly in other bottoms.