They are incredibly cool, and awesome, and unpractical.  They are fun to play with in the yard, but is hard to carry along to another throwing site.
I know this, I have brought one of my two into the forest, by placing one behind my belt an having a jacket over it.  It is smooth and heavy, and want to slide up or down, and both of the two points pokes holes in clothing and skin.  When it hits on its flat, it chimes like a bell, so it is a little difficult to practice with them in a discrete way.
If they hit the ground point first, they slide smoothly beneath the turf and disappear.
With other words, lot of fun

Making one from light weight stuff seem like a good idea.  But of course, if this 2 pound thing is thrown at someone in self defense, or at a small animal intended to be dinner, it would not matter that much which way it hit
timann

looks like fun - but you can see from the video that 90% of the time it doesn't hit point first - I can do way more damage with a short sling - and from that distance, probably as accurate.

It is still very cool