It seems that those people who tend to more strictly interpret and follow the rules (whatever they are - laws, regulations, procedures, whatever) have greater efficiency when everything is going as expected.
Those who are more flexible with rules tend to do better when things aren't going as expected, and when you really need customer service, it's usually because things haven't gone as expected.
Working in technology, and watching the interaction between the these-are-the-rules people and the what-if-we-break-some-rules people is intriguing.