Walls and Dongell: "...God arranges the world as he chooses based on his middle knowledge. God exercises sovereign control in the sense that he creates the person he wishes to create and brings about the circumstances he wills, knowing just what choices all those persons will make in the circumstances he has brought about." (Why I am Not a Calvinist, p.137)
Walls and Dongell: "Unlike the Calvinist determinist, the Molinist believes God's decrees are dependent on what he knows creatures would freely do in various circumstances." (p.137)
Walls and Dongell: "Molinism is an attractive position in many ways. It offers an account of providence that explains how God can have a highly particular degree of control over various circumstances without resorting to determinism of human choices. For those who are attracted to Calvinism's account of providence and sovereignty but are hesitant to embrace determinism, Molinism may seem like the perfect alternative." (p.138)
In my opinion, it offers a very logical explanation for Genesis 50:20. One of the Bible's clearest examples of Middle Knowledge is found at Matthew 11:20-24. Moreover, I believe that 1st Corinthians 10:13 also lays the groundwork for Middle Knowledge. So is Middle Knowledge a middle ground that Calvinists can embrace?
Walls and Dongell: "...at the end of the day, Molinism is not a compromise position that Calvinists can embrace; rather, it is a variation on Arminianism. As Muller has recognized, if Molinism were accepted as a middle ground position, 'the Reformed would need to concede virtually all of the issues in debate and adopt an Arminian perspective.' It is clear, then, that Molinism, despite its strong account of particular providential control, does not represent enough divine control for the truly Reformed." (pp.138-139)
Perhaps the reason for this, is because for Calvinism, God's knowledge does not guide His decrees, but rather, His knowledge is the result of His decrees, insomuch that God's knowledge is the "transcript of His decrees."
Additionally, here is an interesting article that I located concerning Middle Knowledge.