Thank you very much for a very illuminating reply to my query. You have clearly experienced situations that put extreme stress on whatever equipment you can provide and you clearly make the case for legitimate needs for extremely tough blades that can suffer abuse and not break.

Interesting, my current needs are a bit closer to normal. I, too, dig in rocky soil, usually while backpacking or hiking, often at distance from a vehicle, but I am retrieving fossils, and the pace is somewhat more leisurely than what you experienced. I find that I need a fine digging tool (pointing trowel, sharpened) and more and more often, a rough tool, typically used to pry rocks out of the way. Balancing weight and utility, I more and more often pack a small (8" or so) pry bar. And I improvise and adapt a lot,using rocks for hammers etc.

Your comments about e-tools are interesting. I have a WWII style e-tool in my vehicle and I find it very useful at digging out the car from time to time. Love the easily adjustable blade. Also useful for the occasional fossil...