I disagree. I think how appealing and easy your file is why people are getting their visas in 6 months and some are taking 12 months.
If your case is clear and open, they have all your documents - they don't want to stress themselves out in chasing down and doing some other research regarding both sponsor and applicant.
Also I think how the file is organized is another big thing, if it's neat and looks presentable then that speaks volumes to officer. It makes his job easier at the end of the day.