I've been on the Magnesium Glycinate 200 mg for about a week. So far, no reduction in headaches, though some sites say it can take weeks or months to notice a difference.
On the bright side, I'm sleeping much better. (Some studies indicate that magnesium helps with sleep.) And I don't have the diarrhea issues that the other magnesium pills caused.
I'll keep experimenting with the magnesium, CoQ10 and Riboflavin and post when I have an update.