CoS steel and Fallkniven Kolt

[Chris Larrikin]

G'day. I'm considering buying a Fallkniven fixed blade and just came across the Kolt. It's described as having a laminated blade with CoS steel for the core. I haven't heard of CoS and a quick look online tells me that it's a newer steel from Takefu. I'm just wondering what the good folk here can tell me about CoS, edge retention, sharpening etc - all the usual stuff. Cheers!