From what I've seen on WWII gun cam films.it appears that most pilots used tracers.One about every tenth round.I watched an interview with Bud Anderson,and he said he only used tracers at the end of the belt to let him know he was getting low on ammo.He also stated he didn't care which Pony he flew as the lack of a pair of MG's didn't bother him.Personally I would like the 6 MG package,as with 4,it's assist city for me.
In the game,and with all the ho-ing taking place,tracers off is probably best.With all the face shooting going on,there will be collisions,and we all have had this one happen.The bad guy collides with you ,you get a ton of damage,and die,and he gets the kill.it also works the exact oppsite.I have seen a oncoming bad guy fly close to me and never hit me,and he gets a collide message!If they ever fix that aspect of the game it would be nice.
I use tracers off most of the time,but will switch once in awhile.I spray and pray,so it doesn't matter for the most part.
The Dawg