Sir Gregory Hall, Esq. wrote:
SNIPPED
Anchoring has so many variables that any one test run means very
little in the overall art of anchoring. And, it is an art. The
sailor (artist) must have a variety of anchors at his disposal
and know how, when and where to use each one. About the only
thing that makes the sailor proficient is experience, experience
and more experience in all manner of holding grounds.
Expecting one particular anchor to work well or even adequately
in all holding grounds is folly.
That is about the first sensible thing the Craptain has posted; and that
is something I thought I would never write.
Most of the recent anchors like the Rocna are a gimmick and
not as reliable as the older patent anchors. That people pay
such exorbitant prices for these dubious anchors is folly.
That I cannot agree with. Understanding of how anchors 'work' has
developed over the years, as have manufacturing techniques.
To add to your experience, the Rocna and similar copies have been
thouroughly tested since their inception by many reputable boating
mags, websites and organisations. They continue to stand out among
the best. I'd love to try one vs my quite heavy Danforth - but they
are quite dear! 
Sailing in NW Scotland and points further north, anchoring is the norm
for me. For my last boat (Nicholson 32) I got one of the first Rocna's
to be imported into the UK. I found it to be a significantly more
reliable than the CQR (15Kg both) and, contrary to Duncan McCormack's
experiences, set very quickly. It held in windy situations when I was
quite worried. When I changed boats last year (Rustler 36 now) I got a
Rocna 20Kg before I took the boat out.
Tony H