Tazman, and PatapscoMike,
You will note that the mech head I have on the webpage shows the angle from the tip to the tips of the blades in different stages of opening.
Starting out, the mech head was at a maximum angle of 32 degrees (similar to the S/T) but growing to 41, then dropping back to 21.
IMHO, the problem with the deflection issue is when the head hits bone. On deployment, the skin will give as the head opens (blade opens about 1/8" before dropping back to a shallow angle).
Another benefit of the mech head, was that when shot through bone, the aluminum ring that stops the blades would get hit hard enough to make grooves when the blades hit it. this allowed the blades to extend further rearwards (more shallow angle...smaller hole). ON the head I tested, that was worth a few more degrees taken off (NOT the one in the pic).
That said, the Muzzy was at almost the SAME angle as the mech head, and the cutting edge head was better still.
Oddly enough, in my tests the mech head and the slick trick did best in penetration through bone. Most likely due to the large tip on the mech head allowing the rest of the head, and arrow to follow unrestricted, and the short didtance from the tip to the blades on the slick trick allowing the hole to be made large very quickly as well.
Gimme a Muzzy with the point from the shockwave, and you'll have a nearly perfect head (In MY book anyway :-) )