The SRK is a pretty big and hefty knife. I have lots of Cold Steel knives (some even larger than the SRK!), bought many many years ago. I never use any of them. I guess they would be good if I needed to penetrate a hippopotamus or something, but I just found no practical use for them. I think when I was young I must have imagined a rampaging hippo might make it to Colorado where I'd need to defend myself. My SRK (now given to my son) is so old it's made of what they used to call "Carbon V", which I think was their marketing term to mean, "Even WE don't know what's in it!"

I'm sure that Carbon V is far inferior to any of the steels you can now get an SRK made from, so my opinion would be that any of the steels mentioned would serve the purpose admirably, if you actually have a purpose for a hippo-stabber.

p.s. - Full disclosure: My experience with knives is from a civilian camper/hiker perspective. My thoughts might be different if I were military and having to dig up land mines from under a foot of sand with my knife.