I chose no flash cards, but not because we don't drill facts. We use a variety of games and apps to drill math facts, for instance Timez Attack, Reflex Math, xtra math, QuickMath, to name a few. I just think it's more fun than flash cards and also because it is something that can be done independently, freeing me up to work with a sibling.
ETA: We use Beast Academy and Math in Focus.