You haven´t snapped THIS crank, simple fact that you managed to snap one crank after x years of riding doesn´t mean shit anyway, every crank is going to break if you try hard enough.
There are lighter cranks and they don´t have weight limit, I don´t see the reason why these should have, I bet they are MUCH stronger/stiffer than those lighter cranks. But my ankles hurt just looking at them lol.
Should be easier on the back wheel too, so if you want disc brake, it should be good buy. If you want to see it in action I think these Triboulat(spelling?) brothers ride on them.
I found vid for you