That's why I like the CRKT M16 family.
1. Opens & locks quicker than a butterfly. One flick of the wrist with a push on the Carson Flipper will open & lock the knife or thumb stud will open.
2. The lock is much, much better than the butterflies I'm familiar with.
3. IIRC some places consider the butterfly to be a switchblade.

I finally found a description & pictures on their website.
CRKT Auto-LAWKS

On the one I've got the blade locks almost as solid as a fixed blade. The only movement is the space needed for tolerances. The liner lock is blocked from being moved out of the path of the blade by the spring loaded yellow piece in the drawing.