For those who are obsessed with corrosion resistance (like me...), and for those who want a knife that is non-magnetic but still wants a really tough, strong knife, there aren't many real options. Zirconia ceramics, the various Stellites, Nitinol60/SM-100, Liquidmetal/Vitreloy, these are not bad materials, but they have limitations, either in toughness or tensile/yield strength. None of which are as durable and tough as Mission's custom heat-treated Beta C titanium alloy knives.
Let's say there is a nickel-based alloy, or rather a small, three-membered alloy family, whose mechanical properties, hardness, which is 58-63 RC with aging heat treatment (~67 RC with cold working+aging, but at this value there is probably no meaningful toughness), tensile strength (320-390 ksi), elongation (~2%) are not worse than the properties of better steels used for knives.
Their wear resistance is certainly worse than that of steels with higher carbide content, because there are no ultra-hard carbides in these alloys, but it is presumably acceptable.
And they are extremely corrosion resistant. In salt water, they are slightly worse than titanium, but better than all steels, even steels similar to 316 austenitic steel. Their corrosion resistance can be roughly at the Stellite 6/Talonite level, or slightly better. But unfortunately these alloys are almost impossible to obtain (the basic alloy is currently only produced in Russia and Japan, and its improved versions only in Russia), and they are not available in plate or flat bar form at all, but only in round bar or wire form, as far as I know.
Therefore, I think that until these alloys become available to knife makers, Mission Knives' titanium knives will remain the best alternatives to steel knives, even with their relatively low hardness, if someone is looking for a non-steel knife for heavy-duty use.
So it would be nice if they really made a comeback soon.