The "gamey" advantage people are referring to is turning off your engine sound. That will allow you to more precisely hear when planes are approaching you, and if your opponent is tinkering with his throttle. It will also kill your sense of immersion, and really, by the time your skill level reaches a point where it will be terribly useful for you in a 1v1, you'll already be able to eyeball/estimate your opponent's throttle work to a fair degree, anyway.
I do turn it down a bit as I have trouble hearing muffled noises, and if I left it at the default I'd never be able to hear my flaps, friends, gear, etc. I think I have it set at around 45 and have found it lets me keep pretending I'm actually flying a roaring aircraft without losing the ability to hear anything else.
As others have said, it's a personal preference.