Here is part of the Free Reformed Study Committee on the NKJV and the TR in general:
Among all the major new translations (smaller efforts by Jay Green and others aside) since the end of the nineteenth century, the New King James Version is the only version that explicitly holds to the Textus Receptus as its base. The 1990 Preface to the NKJV notes: "IT]he editors decided to retain the traditional text in the body of the New Testament."
It is important to note that the authors of the NKJV did not just wish to produce a Bible in today's language because there were already dozens of contemporary versions on the market. What they wanted was a version that was based on what they considered the best manuscripts available, namely the Textus Receptus or the Majority Text which also underlies the AV. As Dr. Arthur L. Farstad, Executive Editor of the New King James Version wrote: "the NKJV is an update of an historic version translated from a specific type of text. We felt it was unwise to change the base from which it [the Textus Receptus] was made..."' Arthur Farstad along with Zane Hodges are the two most recognized defenders of the Majority Text in America in recent years and they have done much to revive an interest in this text among N.T. scholars.
The 1990 Preface sketches the textual critical scene as follows:
The King James New Testament was based on the traditional text of the Greek-speaking churches, first published in 1516, and later called the Textus Receptus or Received Text. Although based on the relatively few available manuscripts, these were representative of many more which existed at the time but only became known later. In the late nineteenth century, B. Westcott and F. 14oft taught that this text had been officially edited by the fourth-century church, but a total lack of historical evidence for this event has forced a revision of the theory. It is now widely held that the Byzantine Text that largely supports the Textus Receptus has as much right as the Alexandrian or any other
tradition to be weighed in determining the text of the New Testament. Those readings in the Textus Receptus which have weak support are indicated in the side reference column as being opposed by both Critical and Majority Texts. Since the 1880s most contemporary translations of the New Testament have relied upon a relatively few manuscripts discovered chiefly in the late nineteenth and early twentieth centuries. Such translations depend primarily on two manuscripts, Codex Vaticanus and Codex Sinaiticus, because of their greater age. The Greek text obtained by using these sources and the related papyri (our most ancient manuscripts) is known as the Alexandrian Text. However, some scholars have grounds for doubting the faithfulness of Vaticanus and Sinaiticus, since they often disagree with one another, and Sinaiticus exhibits excessive omission.
A third viewpoint of New Testament scholarship holds that the best text is based on the consensus of the majority of existing Greek manuscripts. This text is called the Majority Text. Most of these manuscripts are in substantial agreement. Even though many are late, and none is earlier than the fifth century, usually their readings are verified by papyri, ancient versions, quotations from the early church fathers, or a combination of these. The Majority Text is similar to the Textus Receptus, but it corrects those readings which have little or no support in the Greek manuscript tradition.
Today, scholars agree that the science of New Testament textual criticism is in a state of flux. Very few scholars still favor the Textus Receptus as such, and then often for its historical prestige as the text of Luther, Calvin, Tyndale, and/he King James Version. For about a century most have followed a Critical Text (so called because it is edited according to specific principles of textual criticism) which depends heavily upon the Alexandrian type of text. More recently many have abandoned this Critical Text (which is quite similar to the one edited by Westcott and Hort) for one that is more eclectic. Finally, a small but growing number of scholars prefer the Majority Text, which is close to the traditional text except in the Revelation.
In light of these facts, and also because the New King James Version is the fifth revision of a historic document translated from specific Greek texts, the editors decided to retain the traditional text in the body of the New Testament and to indicate major Critical and Majority Text variant readings in the marginal notes. Although these variations are duly indicated in the notes of the present edition, it is most important to emphasize that fully eighty-five percent of the New Testament text is the same in the Textus Receptus, the Alexandrian Text, and the Majority Text.
When one compares this preface with the preface of the 1982 edition of the NKJV, we do find somewhat of a shift. In 1982 the editors wrote the following: ".... a growing number of scholars now regard the Received Text as far more reliable than previously thought. In light of these developments, and with the knowledge that most textual variants have no practical effect on translation, the New King James New Testament has been based on this Received Text, thus perpetuating the tradition begun by William Tyndale in 1525 and continued by the 1611 translators in rendering the Authorized Version.'''