I agree. Toughest really is all inclusive. Edge hardness in not related to toughness at all it's separate. Knives/Tools can have extremely hard edges and be very brittle. Toughness is a materials ability to resist breaking it's mechanical, Hardness is it's ability to resist abrasion/wear and strength is it's ability to resist deflection/taking a set. SR77 is just as "tough" as "INFI" but has less wear resistance. Friction forged knives look like they might be good for soft chores such as skinning and such but not for really hard use. Which is OK from there web site it looks like that is the nitch their trying for.

As far as all around toughness I don't think it gets better than Busse at this point in time.