Hope your hand is better now.
I have been carrying the new zytel delica and endura for abt a month now. Both are tip up.
The delica handle has a longer curve under the edge than the endura for your first two fingers/or first one finger. When I hold the delica, I put my first two fingers on this curve, but with the endura, I put only my index finger on this curve, because there's not enough space. I thus hold the endura closer to the butt, which is OK for a hammer grip for rough movements, but for finer work I will choke up on the handle to put my thumb on the back of the hump.
Both the new zytel delica and endura can be carried right or left, but only tip up. I don't mind tip up because I usually carry the knives clipped to my side pockets with vertical seams. Tip down may be better in jeans-style front horizontal pockets,etc.
When I pull the knife from my pocket, I don't try to get my thumb in the hole immediately. I think this is adding excess motion. I put my index finger on the tip of the clip, my middle finger on the side of the clip, my thumb on the flat surface of the zytel handle. As I pull the knife out, I turn my wrist palm up and my thumb goes naturally into the hole. Continuing the motion, I flick the blade open with the thumb, then put my thumb on the zytel handle, pinch it between my index finger and thumb, turn my palm sideways, get my last three fingers around the handle and get the knife into a hammer grip.
It sounds lengthy, but so far it seems the fastest way to do the thumb opening from tip up, IMHO.
The shake and flick open I can only do with the endura. I grab the knife as described above but don't do the palm up. I shake the knife down hard(the zytel is rough, so there is some friction), making sure that sufficient force is used, and my hand jerks to a stop to send the blade out. Then I flick the wrist outwards to lock the blade.
Only disadvantage is that more space may be required to open the knife, but it may be faster than the thumb flick.
Anyway, I'm sure you know this.
Best wishes for your recovery from SYK
[This message has been edited by SYK (edited 08-12-2000).]