In Real Life, were there pilots who chose to loadout without tracers? Were they even allowed to make that choice?
Can't give you a comprehensive answer on this, but I do know that at least several 8th AF squadrons were going no-tracer by the end of the war. All of the accounts I've read reported that their kill rate improved dramatically. I imagine there were various reasons for this, not least that tracers don't have the same trajectory as the non-tracer ammo and, as others have pointed out here, tracers over your canopy provide an unmistakeable warning that you're a target.
In AvA, where we've been flying no-icons for a bit more than a year, it seems to me that virtually everyone has turned tracers off.
- oldman