Hello all, I own both a Etrema Ratio KL, and the KS model, the KL has a more narrow blade from the spine to the cutting edge and is designed for jungle and swamp use such as clearing palmetos, and under growth, to choping soft woods the KS has a wider blade from the spine to the cutting edge and can really do a lot of the same its just more compact, they are both great chopper, and have a thick spine almost 1/4'' thick, they do hold a razor sharp edge, and they really have a give great bite. the one and only flaw that I personally can see is that even though they have a full tang construction, the handles are removable for ease of cleaning, personally I would rather have the handles be attached simmilar to the busse where there is no room for play, but other then that they are fantastic. they are a little tricky to sharpen but the hold thier edge for quit some time so unless your chopping through steel pipes you really shouldnt have to sharpen after every use.