I always thought that they were a good idea. BUT.They are limited to pretty much thrusting.
I read somewhere that courts tend to see slashes and cuts as defensive and stabs as offensive in nature. So that may come back on the user. Also ,they can kind of work the inside of the fingers bracing the blade stem.Trying to get decent slashes was a chore as the unit can twist in your hand. Not much,but enough to turn the cut. I worked with a cold stell double edged version.In holding the unit it seemed fine. But when I worked it over on a piece of rolled carpet, a couple problems popped up. First,its just not that steady,had to really postion myself for a thrust-punch. The unit isnt really stable in a ballistic situation. You get jumped and are trying to get in position,while somebody is working you over. Cant do a number of techniques due to this limitation.Also on the slash, the blade didnt have any follow through.Due to not having a handle.
This isnt to dump on cold steel, Its just a push dagger thing,I hope they understand.
also again in the aftermath, if you survive the encounter it would suck to get in trouble because your"push DAGGER" (as the prosecution would call it),scared a jurior.