I think the rotation of 65% vs 18% is an oversimplification. Where is the center of gravity. One must take the entire anchor into act. I've never watched one "pop" out.
As for holding in hard bottoms and
grass those are always tricky situations. Up the weight of an anchor, any anchor for the hard bottom and eventually you'll be able to pierce it. If not than go to a different anchor.
When we first started crusing we had a 35 lb CQR. I had some difficulty digging in at times and a little dragging. Boat was a 20k lb
cutter. I upped the weight (new anchor) to a 45 lb CQR and never had the problem w/ piercing the bottom again. My cruising area was
Florida,
Bahamas and N
Carribean north of the VI's. In light
grass it held fine but in heavy grass I needed to go to the Luke that I carry.
Of course the anchoring delima can't be fully understood w/o the discussion of rode. And while anchor tests often just compair anchors they never really
work rode into the situation. Nor are there many scientific rules applied; ie they compare anchors of different weights to each other, there is no comparision of same style anchor to different weights in that style, there is no compairson of different
scope lenghts to the same anchor.
The Sail test was interesting, but anchoring on the 3 / 1
scope seemed bizare to me. While one may begin setting the anchor at 3 / 1 I don't know any "cruisers" that anchor on 3 / 1. Those that do soon learn and change to a longer scope.