the biggest difference for me is I like tracers for bombers and AA guns, but prefer no tracers for fighters. Invevitably my first flight or two in fighters after using bombers/aa I keep lighting up the sky with tracers that obscure my aim. Or in my first flight or two in a bomber, I fire hoping to get a feel for the trajectory... but have no tracers

the ability to set tracers on or off for each independent aircraft/vehicle/manned AA would be an excellent feature.