I have. Fit and finish are good, with nice and even grindlines. depending on the model and on the serie you will find either a soft rubber handle with a high seizure pad ( think about it as heavy duty velcro) or a harder compound full handle.
the steel was originally used to make meat grinders blades, so when heat treated properly it should be togh enough. Go for a new 58 hrc hardness model,though : the older 60 hrc models hare too hard(expecially when you consider the cross section of the tip ). The harpoon is an excellent fighting knife, while the golem/fulcrum series are most suited to heavy duty work.