Molinism & Calvinism: What's the Difference?

Molinism holds that logically prior to God's decree of a world God knows what various creatures would do in various circumstances in which you might place them and how they would freely react. So by decreeing to create just those people in just those circumstances and then leaving them to do as they want God knows exactly what will happen. So people are predestined in the sense that God knew exactly what they would freely choose to do in the world that God has decreed, and yet they are free to do whatever they want and to respond to God's grace or not as they will. It's been rightly said that on Molinism it's up to God whether we find ourselves in a world in which we are predestined, but it is up to us whether we are predestined in the world in which we find ourselves. The Calvinist finds this unacceptable because it is not God who determines how creatures would freely act in various circumstances. The Calvinist insists that an absolutely sovereign God must himself determine how creatures would act in various circumstances, and so God unilaterally determines to create these creatures and these circumstances, and he determines what they will do in those circumstances so that everything is foreordained and predestined by a kind of unilateral divine determinism which is incompatible with the libertarian free will that the Molinist is so anxious to affirm.