A lot of guys trim very closely because it makes the total length look longer
Muffinthemoo: How many guys have you hob-knobbed with then? Never trimmed so I can't confirm your observations. 
Actually this thread came up at an opportune moment ; I was talking to a chap recently who had replied to a job advert asking for interested persons to apply for jobs as "meticulous groomers" to work for a modelling agency. He had a successful interview and the interviewer said, your in, and here's your rail pass to Ballarat. ( a small country town about 80k North of Melb.) The chap asked "why do I have to go to ***Ballarat"? The reply was "that's the end of the queue!"
Remember Victor Meldrew in hospital for a procedure when a "Nutter" enters his room, wearing a white doctor's coat and carrying a cut-throat razor? He then proceeds to shave Victor's "nether region", carefully moving Vic's appendage from side to side as he shaved. It was a scream, beautifully acted and even had me squirming in my chair. Needless to say, two other gents in white coats came and removed the "Nutter". They don't write comedy like that anymore! 