So far this new type of goshinken has held up pretty well. It's only been a month of use but so far nothing immediate.
We've tried it among the senseis and brown belts and it certainly held up. The entire class has used it (swapping it between people) for sparring and kata practice. They're getting used to others using it on them.
Wear and Tear
The grip is holding. Even with very hard smacks the is no paint chipping, cracks, tears, breaks, permanent kinks or bends. When you swing, you can see the goshinken bend with the acceleration but this is nothing really.
I've whacked it hard against a table top and nothing.
I have not tried it against a rough surface like a rough concrete or masonry pillar or wall. I think it might scratch or tear the material.
There is no obvious break point at the tip like the older ones have.
A soft hit creates more impact than the old goshinken because the force gets focused along the edge.
A hard hit (by me or sensei Andrew on ourselves) hurts and lasts for a minute but there's no bruising (immediate or delyaed).
Multiple hits onto the same spot do hurt because you haven't recovered from the sting yet.
This kind of pain is hard to tell but they are definitely more painful than the old ones.
It is still expensive at $95 (after shipping is included) but I think this will last much, much longer so its worth it in the end.
At this point, I'd say it is safe to buy and use for the class. I'll see about getting it as a standard item at the Kodenkan of Tucson, so people can order it easily. (keep in mind its free shipping when you get it from KoT saves you $8 at least)