Randal O'Brian wrote:

The reason hardened tool holders are desirable is that under hard use the
insert pockets don't wear and the shanks aren't deformed by the QC holder
set screws.

I have yet to see the first and fail to see why the second matters.
Appearance?

Also, in case you screw up, the insert breaks with less chance
of damaging the tool holder nose or the retaining screw hole(ask me how I
know).

Again, while I have broken a few inserts in my time, I haven't damaged
my mild steel holders.

nearly the same modulus of elasticity. And no, Ted, not everybody is as
"thrifty" as you areG.

I'm happy for you that you have miney to burn. Not all of us are so
fortunate. :-)
Ted