I have a 6-pack of 150gr KME sharpened Concordes, RH single bevel. Haven't gotten any blood on them yet. But was curious to see how durable they are, so I took one of heads and hammered it with a rubber mallet into a 2x4. The ferrule can be a source of skepticism for some people but it held up from the impact of the mallet just fine with no sign of deformation. Went up and down the length and split the 2x4; the head was no worse for wear at all.
Thinking of getting some Aztecs as well once Tim gets a new shipment in. Highly recommend checking out this one unscientific test conducted on an Aussie forum where the Aztec beat out more expensive competitors when shot through a heavy duty skillet. Bear in mind that the Aztec has thinner steel than the Concorde!! And now that they permanently dropped the price, the Tuskers are a truly unbeatable value (in my eyes) for the dollar you spend.