some airplanes lend themselves to using the tracers off option but I find that most cons see me before I fire due to Icons and my extreme angle inverted or what have you firing solutions find their mark easier w tracers.
its a trade off between surprise and ability to aquire a firing solution in extreme deflection circumstances and long ranges.
however if icons are turned off I will be the first to load my a/c w no tracers since the advantage and surprise it gives is much more significant.