I don't know about either representation, really. It seems to me that the whole "streaking" tracer thing is a function of film characteristics, that not only streaks the hotspot on the film but the burn-in enlarges it a small amount due to film local over-exposure. Whenever I've fired tracers all I ever see is a dot flying along. I think it would be a whole lot more "realistic" to just show those small dots.

I'm on vacation ... WOOHOO.