Re: Soft vs hard (correct?) kote gaeshi?
Wrist locks that function largely as attacks to the joint are beatable by anyone who does enough strengthening work that they can't be torqued on any more. Also, anyone who has done full contact work is used to dealing with impact and pain and is often quite able to take a wrist strain or even a break and stay up and knock you out with his other functioning limbs.
I think it is important to remember that our technique was originally about weapons. If you are trying to defend against someone with weapons it is far more important to have the attacker down and in a position that one can finish him, either with a pin, if the situation allows, or with a finishing strike(s) either with empty hand or with ones own weapon.
The best techniques are the ones that put the attacker on the ground and do not function because of pain or injury to some peripheral appendage but rather catch his center and take away his ability to continue his offense. In my own work, if it hurts, the energy of the technique is in the wrong place.