these knives are called "double-action" or "dual-action" as not to be mistaken with the double action of autos that also retract (microtech)
hence the name "double" duty
its not the best made auto out there but its still cool. i think the scale firing works faster than some bolster firing ones, and definately faster than button fire.
i've owned one for about 6 months now, the G10 version. take if from me, be very careful not to fire the spring when the blade is already out.
it some how screws it up so that each succesive fire, the spring over extends and prevents the liner from passing over and locking the blade.
this happend when i first got mine, I sent it back and got another one and it happend again.
I ended up taking a dremel and putting small bevels on the spring and the liner so they could pass by each other.
i think they could have worked on the design to make more "sense' when the knife is closed. the tang sticks out too far IMO. also the clip could have been designed better.
but its my favorite EDC besides my strider and s30v leek.