[marshall]

Originally Posted by Cory

The obsession with hex is because round keyed stock is completely inferior in every way (except perhaps availability).

Strength (massive stress risers)
Ease of use...no keys to lose during installation. No struggling to get the key in/out of the keyway on either mating part. No need to cut keys.
Torque transmission (which goes into strength)
The list goes on and on.

It's true! It's all true! I was against hex for a while but I have to say, I've been converted.