Personally I think turning tracers off is one of the most over-hyped aspects of aerial gunnery in the game.
If there's an actual advantage, it's that your opponent can't see your misses. And really, that's only an advantage if your gunnery is so bad you can't hit someone who's unaware of your presence.
If your gunnery is so bad you can't hit someone who's unaware of your presence, you need feedback to allow you to correct your aim. You only have that if your tracers are on. Tracers may very well allow you to correct your aim before he can react anyway, even if they alert him to your presence...
How do you learn anything in life? With feedback. With feedback, you know. Without it, you guess. When learning something, is it better to have the facts, or just a guess?
Throw a rock straight up in the air, and shoot at it with a .22. We'll assume you missed it. Did you miss it to the left/right, high or low? How do you know, since you have no feedback? Now, correct for that mistake with your next shot. If you missed low, aim higher, etc. But wait, how do you know if you shot low? Maybe you think you shot low, so you aim higher, but in actuality, you may have initially missed it to the right... How will your "guess" of where you missed help you? What if you think you missed a foot low, so correct for it, but you really missed 6" or 18" low?
Even if you eventually hit it, what have you learned? Nothing. You just randomly hit the stone. You got lucky. You didn't learn (for example) that you have a tendency to aim low...
Now, try the same exercise with tracers... Shoot at the rock, but miss low. Now, do you know you missed low? Yup. Do you know you missed low by 12", vs 6" or 18"? Yup. Can you intelligently correct for it? Yup. Over the course of a day's shooting, can you learn that you have a tendency to miss in a particular way (low, or to the right maybe?). Yup. Can you begin to correct for that tendency? Yup. Are you learning with "facts"? Yup...
In AH though, you don't always have a target in the same position, offering the same shot scenario. You need to learn a myriad of angles, leads, etc... How will you learn quicker? With feedback.
With tracers off, the only feedback you get is for hits. Those are the shots you really don't need feedback for... Imagine if you were in school, and you only got feedback on tests where you scored 100%.
Imagine throwing a ball, but not being able to see it in flight. If you miss the glove, or the basket, or whatever, how do you correct for it for the next throw? You don't... You can only guess...