That was the only OTC I avoided, specifically because I was trying to tightly control and titrate down the caffeine dose (granted, measuring beans isn't precise dosing, but I didn't want to blow my work out of the water by throwing some Excedrin into the mix).
I don't get migraines very often (once a year maybe), but the first aura was very strange not knowing what it was.
For me they start out as a bright point of light then spreads out into an expanding shimmering arc of rainbow colors. Sometimes the vision inside the arc is ok, other times it is kinda missing. The headache usually comes on as the aura is fading out. Sometimes I get an aura without the migraine.
I get a blind spot near the center of my vision that looks a bit like what you see when you rub your closed eyes. It gets large enough to mostly obscure faces and prevent reading