I have a new Apparition I picked up last week. At first it seemed a little hard to open, but after a couple of days of practice it's snapping open every time. Part of it is getting the blade/stud moving in the direction it wants to go (out and forward in an arc -- not just forward).
When you open it: Make sure the meaty/fleshy part of your thumb is resting on the stud where it connects with the blade, not just on the tip of the stud. Then give your thumb a hard push/flick in the same direction as the arc of the blade travel (not forward, but more out and forward at 45 degrees to the knife body). This really gets the blade opening. At first I was pushing on just the tip of stud (in a forward movement) and it was killing my thumb, and opening about half way.
It took a couple of days for me to get the feel of it, and now it works every time, comfortably and easier.
I really love the knife, great feel, and great looks!
Joe