This problem is not unique to Fortress. Virtually all of the light
weight type anchors with wide flukes will exhibit the same behavior
unless the boat is almost stopped before dropping the anchor. The only
cure is shape and weight. An anchor with a thinner profile such as a
Spade, Bruce, CQR or Plow, with a decent amount of chain on it, will
get to the bottom even with the boat moving. I'd recommend at least a
boat length of chain in most cases, sized to match the breaking
strength of the rode and holding power of the anchor. As a bonus you
end up with an anchor system that will usually reset itself if the
anchor pulls out for some reason.

It is true that a heavy anchor with heavy chain begs for a windlass,
but speed of retrieval is usually much less important than speed of
setting in an emergency situation.

In fairness to the Fortress (and to Danforth's), they have a great deal
of holding power for their weight and are deservedly very popular for
general usage. In addition the Fortress can be disassembled for more
compact storage. I'm thinking of buying a really large Fortress and
carrying it disassembled as an ultimate storm anchor.