From Portland Bolt and Manufacturing Company:
The construction of a Factory Five Mk IV Roadster
"Myth: ‘An experienced and capable mechanic doesn’t need a torque wrench— he can feel the correct tightness and repeat it as close to a torque wrench.’ This is obvious nonsense. The person who can feel any given torque within ten percent, let alone repeat it, has not been born."
From Portland Bolt and Manufacturing Company: