Chuck,

I think that you'll find among the top level professional trainers that FF isn't controversial at all. It is the accepted practice. You CAN train a retriever effectively without it (look at some of the successful British trainers, for instance), BUT you will not be likely to get the best out of your retriever without FF.

You've hit the nail on the head with the statement "fundamental milestone in the dog's training and a building block to more complex training".

Youth is stolen by Wisdom.