Hey there Steve!
I love the SlickTrick broadheads, I use them all the time with the wheelies, so I thought I'd try them out with my recurve - they flew great with those also! Right on with the field points.
A COC (cut on contact) head is a head that has a blade that extends to the very tip of the head. Technically the ST is not a COC head, as the blades interlock inside a steel ferrel. I haven't had any penetration issues, but they do require more pressure to penetrate vs a blade point.
Good news is that SlickTrick did introduce a COC head this year, I believe it's called the Razor trick, which has a 1, 1/8"th main and a 3/4" bleeder. I've shot both it and the new 1 1/4" Grizz Trick that's a little larger than the standard ST Mag. All flew great for me, even in a marginally tuned bow/arrow combination.
I can vouch for the holes. I had no problems tracking with mine. They are proven for me.
Chris