I have the 511, scrapper 6 ( not really a SURVIVAL KNIFE) Nice to have though, Scrapper 5, 411 And The mud mutt. I tend to lean toward the 511. It’s more like the blade shape I grew up with in the mid 60’s into ‘74 when I went into the Air Force. But if I had to grab one without thought it would probably be the S5. The sharper point of the 511 would have me worried in a survival situation. I feel the “spear point” shape would be more robust.