My instructor has one of those, but said that at the moment they were only selling it to LEOs and that the mainstream version would be autoset at the lowest level. I got shocked at the highest level and it feeling kinda like your hair being pulled out where it hits, very noticeable, but not that painful, the advantage of the technology being, I'm told, that only contact is required to make you aware of the damage instead of rubber/metal knifes where you don't get the shock/"shock", but I don't train weapons so I dunno, it was cool though.
Wow, I can't believe I forgot to post my impressions of the shock knife's use during the Dog Brothers GKEH seminar.
While I still think it's a great product for knife tapping drills, or blade awareness drills, it came out pretty minimal in scenario training because:
1 - It runs out of juice way too fast using the supplied batteries
2 - Store bought 9-volts either don't work or are WAAAAY too weak to power the knife
3 - During the adrenaline dump of a good scenario, the "victims" either did not notice when the blade was making contact or ignored it
4 - Some light clothing can render the blade useless for shock value
To expand on #3, there were incidences where I was drawing the blade across my victims neck, could HEAR IT CRACKLING FROM THE JUICE, and they still were ignoring the blade, either because they couldn't feel it or it wasn't "painful" enough to warrant their attention.
All in all, a fun toy for shits and giggles and certain drills, but only if you've got money to burn. I can't in good conscience recommend it.