Well my recently bought curly "R" type striker beat me, try as I might I couldn't get it to throw decent sparks and produce an ember on char cloth.
Been banging away for three days almost constantly and blunted 4 pieces of flint in the process (which is costing me a fortune alone) with no success. So it beat me. Wrote a Email to the vendor (Beaver bushcraft) with my tale of woe and they are refunding me, but I have to send the striker back to them. That's OK I suppose, they will give it a wet and dry sandpaper spruce up and resell it I reckon. Still, it cost me $30 to return it as well.
They did say if I decide to buy another striker off them they will throw in some tinder (probably some amadou and char cloth) and a piece of flint as compensation for the drama for the striker not working properly. They have a good reputation so I am sure that it was just a fluke, and it it did produce some sparks, just not many.
I'll make a decision when the refund comes through, though looking through their list of strikers I do like the look of this one, and they do say it is one of the easiest strikers to use in their line up