All second hand so take it with a grain of salt.
NFL potential draftees from BYU or those who have desires to try out at the combines, etc. have not used his techniques or sought him out for training regiments in preparation for combines, etc.
The agents/consultants hired or retained by potential draftees prior to drafts/combines, etc. are not high on remarks about him.
NFL scouts who are familiar with the program and have familiarity with the S & C program almost to a person hold it in a negative light.
Those are the only three things I've heard but again distantly not directly from players or agents or scouts themselves.