With respect to Reformed and Lutheran differences in understanding, Dr. Gene Veith has made some interesting observations about the significance of Christ's ascension into heaven.  He writes:

It’s odd that the significance of Christ’s ascension is taken in two opposite ways: The Reformed say that it means Christ is ABSENT, no longer on earth, so that His real presence in the sacrament is impossible. Lutherans say that it means Christ, at the right hand of Power, His human nature assumed into the Holy Trinity, can now be omnipresent, so that He CAN be on every altar.

Much of this tracks directly to Calvin and Zwingli's philosophical understanding (and presuppositions), which creates marked theological differences between Lutheran and Reformed theology.  Dr. Veith, without a doubt, has succinctly captured the essence of these differences and their consequences in his practical and easily understood words.