I worked my way backwards through some articles by Evans to his published dissertation. I’ll need to do further reading from adherents to these different positions in order to really evaluate Evans’s presentations.
Evans, William B. “Three Current Reformed Models of Union With Christ,” Prebyterion 41, nos. 1-2 (Fall 2015): 12-30.
The three models that Evans notes are the “bifurcation model,” which he connects especially to Michael Horton and others at Westminster, CA; the “pneumatological-realism” model, which he connects to Geerhardus Vos and Richard Gaffin; and the “pneumatological-incarnational realism model,” which he connects with Calvin, John Williamson Nevin, the Southern Presbyterian John Adger, Thomas F. Torrance, and Robert Letham. It seems to me that Evans is least inclined toward the “bifurcation model” and is most inclined toward the “pnumatological-incarnational realism model.”
Evans, William B. “Dèjà Vu All Over Again? The Contemporary Reformed Soteriological Controversy in Historical Perspective,” Westminster Theological Journal 72, no. 1 (Spring 2010): 135ff.
This article also divides union with Christ views into three groups: (1) “Vos, Murray, Gaffin, et al”; (2) “The Revisionist Wing—Norman Shepherd and the Federal Vision,” (3) “The Repristinationist Wing—Westminster California.” The “Dèjà Vu” part of the title is due to similarities that Evans sees between these contemporary divisions and similar divisions in the 19th century. He thinks the Federal Vision and New England Theology are similar in their “repudiation of merit, and the foregrounding of sanctification,” though not in their ecclesiology. He thinks the Repristinationist Wing is similar to Hodge and the Princetonians because of their strong defense of federal theology, the ordo salutis, and the Law/Gospel distinction. He links the Vos, Murray, Gaffin group to Mercersberg, Shedd, and some Southern Presbyterians.
Evans, William B. Imputation and Impartation: Union with Christ in American Reformed Theology. Eugene, OR: Wipf & Stock, 2008.
This reworking of Evans’s dissertation looks at the theme of Union with Christ in Calvin and the Reformed Orthodox before turning to Edwards, the Edswardeans, Nevin and the Mercersburg School, and the Hodges at Princeton. He notes different ways that union of Christ has been related to other elements of soteriology and the impact those different configurations. The tone seemed rather negative, focusing on descriptions of how different configurations caused various theological problems. Noting such things is necessary, but I would have appreciated having this balanced out by noting the positives of each position culminating in a clear statement of the way forward.

In this volume Wellum and Gentry embark on the ambitious project of laying out a third way between covenant theology and dispensationalism. They label their position New Covenant Theology or Progressive Covenantalism (others who hold a similar position are Tom Wells, Fred Zaspel, John Reisinger, Thomas Schreiner, and Jason Meyer). [Update 4/21/16: The authors wish to distinguish PC from NCT. The two share some similarities, but they do not wish them to be equated. Since Schreiner and Meyer both contribute to the new book on 
Here once more we are reminded that our Lord’s method must ever be the pattern and example for all preaching. That is not true preaching which fails to apply its message and its truth; nor true exposition of the Bible that is simply content to open up a passage and then stop. The truth has to be taken into the life, and it has to be lived. Exhortation and application are essential parts of preaching. We see our Lord doing that very thing here. The remainder of the seventh chapter is nothing but a great and grand application of the message of the Sermon on the Mount to the people who first heard it, and to all of us at all times who claim to be Christian.