One thing that you will find in these books is an emphasis on "consistent literal interpretation" of the prophets. In other words, when the prophets speak about Israel, they can only mean Israel and they cannot be pointing forward to the church. As a result, they imagine covenant theology to be "replacement theology" in which, when God's plan to save Israel failed when they rejected Jesus, he adopted a plan "B" and decided to save the church instead, leaving a lot of OT promises unfulfilled. For dispensationalists, the millennium functions in large measure as a space of time during which presently unfulfilled OT prophecies may find a literal fulfillment.
While we can commend our dispensationalist brothers and sisters for taking OT prophecy seriously and desiring to believe God's Word, there are some hermeneutical issues with this approach. First, they don't actually take every OT prophecy literally. For example, the visionary temple in Ezekiel (which they imagine to be describing a millennial temple) has sacrifices that are designed "to atone" (lekapper) for God's people. But though they have a variety of explanations how you can still have animal sacrifices after the death of Christ, none of them involve the plain reading of the text. Even within dispensationalism, there are debates about just how literal you have to be. Ryrie is very strict, arguing that the battle in Ezek 38-39 - which he sees as a future final battle - will only be fought with the exact weapons mentioned - clubs, spears, etc. Other dispensationalists (e.g. Clarence McCartney) argue that these weapons represent figuratively modern weapons, but Ryrie is correct in seeing the danger of that approach. Once propehcies about clubs and spears become rifles and machine guns you've already opened the door for prophecies about Israel to refer to the church. You are no longer committed to consistent literal interpretation. Besides, the NT specifically takes OT prophecies about Israel and applies them to the church (see Hebrews 8, where the prophecy of a "new covenant" originally addressed to "the House of Israel and the House of Judah" applies to the church). In these passages dispensationalists are forced into allowing a double fulfillment - first to the church and then to Israel. But if the fulfillment in the church is a legitimate fulfillment, why do we need the second one? And why can't we apply the same hermeneutical principles that the apostles did when we look at other prophecies?
As far as "replacement theology" goes, this flows out of a misapprehension of what covenant theology teaches. We do not believe that the church has "replaced" Israel; rather, that Christ has come to be the final and true Israel (see Matthew's use of Hosea in Matt. 2:15). Jesus is the true son, the true vine, the olive tree - all OT images for Israel. The church becomes the new and true Israel as we - Jews and Gentiles alike - are incorporated into Christ as vine branches and olive twigs. So it is really more of a "fulfillment" theology than a "replacement" theology. The true sons of Abraham are not those by physical descent but those who share his faith (see Rom. 4), and thereby are incorporated into Christ.