The release of the “Book of Commandments and Revelations” (BCR) in the latest installment of the Joseph Smith Papers has provided tremendous insights into the textual history of Joseph Smith’s revelations, most of which were eventually canonized in our current edition of the D&C. I have spent countless hours (most of which I don’t have) examining the subtle (and not so subtle) changes that occur in the textual history of many of the revelations.  Marquardt’s volume on the subject has been (and still is to a certain extent) immensely helpful in this regard; however, the BCR was not available to him when he published The Joseph Smith Revelations  and thus the BCR adds valuable insight into our understanding of the textual evolution of Joseph’s revelations.
That said, I have noticed a very interesting phenomenon among Latter-day Saints when it comes to text critical issues in revelation ancient and modern. In dealing with text critical issues in the biblical text many LDS (IMHO) are very interested in getting back to what the bible “really said,” or as the scholarly world has termed it: the illusive urtext. Several scriptural interpretations and/or statements by Mormon leaders seem to have kindled a place for discussions about how the biblical manuscripts contain errors, mistakes, corruptions, etc. I am thinking for example of passages like 1 Nephi 13:40: “These last records. . . shall establish the truth of the first. . . and shall make known the plain and precious things which have been taken away from them,” or statements like Joseph Smith’s when he was reported to have said, “I believe the Bible as it read when it came from the pen of the original writers. Ignorant translators, careless transcribers, or designing and corrupt priests have committed many errors.”  Even the 8th Article of Faith implies that the bible in it’s current state is lacking. Many LDS have no problem getting behind text critical studies of the bible especially when the principles of text criticism “get it right.” For example, the fact that the so-called “Johannine Comma” (1 John 5:7-8) is not found in the earliest Greek manuscripts is helpful to the apologetic LDS who is looking to discredit the idea of the trinity. This many-plain-and-precious-parts-are-lost framework seems to lend itself (in some cases anyway) to many of the works dealing with biblical text criticism that are available today.
Interestingly, ideas change dramatically when it comes to text critical issues in the modern revelations. Most LDS (IMHO) are not comfortable (if they are aware at all) with the idea that our current D&C reads differently than the earliest manuscripts available. This ignorance/uneasiness is unfortunate in that the textual changes can be very informative in helping interpreters to understand the revelations. This can be as simple as attaining a more exact date for many of the revelations and thus a better understanding of the historical setting, to understanding that the final 20 vv of D&C 42 (which were given 2 weeks later) were given in response to questions concerning the first 72 vv.
There are even changes that, interpreted in a certain way, could be read in such as way as to bolster the apologist’s claim to divine foreknowledge. For example, the earliest manuscript of what would become D&C 28 in speaking of the location of “the city,” i.e. the New Jerusalem, originally read “it shall be among the Lamanites.” After Oliver Cowdery and Parley Pratt’s attempt to proselyte “among the Lamanites” was thwarted by the government because of the missionaries’ failure to obtain a permit that allowed them to enter Indian territory, the local Indian agent, one Richard W. Cummins, would describe the situation in a letter to his superior:
“Sir, a few days ago two men all strangers to me went among the Indians, Shawnees/Delawares, they say for the purpose of preaching to and instructing them in religious matters, they say they are sent by God and must preach, they have a new revelation with them, as their guide in teaching the Indians, which they say was shown to one of their sect in a miraculous way, and that an angel from Heaven appeared to one of their men and two others of their sect, and showed them that the work was from God, and much more so. I have refused to let them stay or go among the Indians until they obtain permission from you or some of the official of the Gen’l Government who I am bound to obey. I am informed that they intend to apply to you for permission to go among the Indians, if you refuse, they will go to the Rocky Mtns. But they will be with the Indians.” 
After this first mission to the Lamanites did not work out, the saints had to re-tool their thinking as to what D&C 28 meant. To this effect, Sidney Rigdon in 1831 (under the direction of Joseph?), changed the verse in question to read “it shall be on the borders by the Lamanites,”  a likely reference to Missouri which in fact bordered Native American territory. While, I have my own thoughts and theories (as well as questions) regarding this (and other similar) change(s), it is possible to interpret the original revelation as referring to Utah, especially in light of Cummins reporting that Cowdery would “go to the Rocky Mtns” if necessary. Though I am aware of the historical problems with such an approach, I am simply pointing out that an examination of such changes can produce a variety of interpretations. If one does approach the text in a manner such as this it would seem that the original text is to be preferred.
But the original text is definitely NOT to be preferred in most cases among LDS, at least when it comes to modern revelation. Rather, the latest or most recent text is thought to be the “most correct.” This is a complete about face from how many LDS think of the biblical text, a text that is corrupted, mistranslated, and in need of correction (enter JST). Ironically, it was the Church’s decision to make the BCR available in any Mormon bookstore (including Deseret Book) that brings about many “uncomfortable” questions/discussions concerning the textual changes in the revelations.
In conclusion, I pose two questions to the readers for discussion: (1) What is it in Mormon thought/culture/doctrine that tends to prefer the latest text if working with modern revelations, but prefers the earliest text if working with ancient revelations (not to mention the Book of Mormon text)? and (2) How does the complex textual history of many of the D&C revelations add (or not) to our understanding of the process of revelation(s)?
 Many of the ideas for this post came about through discussions with David G. who blogs at the Juvenile Instructor. Much Thanks!!
 H. Michael Marquardt, The Joseph Smith Revelations: Text and Commentary (Salt Lake City: Signature Books, 1999).
 Joseph Smith, Jr., Teachings of the Prophet Joseph Smith (compiled and arranged by Joseph Fielding Smith; Salt Lake City: Deseret Book, 1976), 327.
 For a work that is written for a popular audience dealing with NT text criticism see Bart D. Ehrman, Misquoting Jesus: The Story Behind Who Changed the Bible and Why (San Francisco: HarperSanFrancisco, 2005). For more technical works see Bruce M. Metzger and Bart D. Ehrman, The Text of the New Testament: Its Transmission, Corruption, and Restoration (4th ed.; New York: Oxford, 2005) dealing with the NT, and Emanuel Tov, Textual Criticism of the Hebrew Bible (2nd Rev. Ed.; Minneapolis: Fortress Press, 2001) dealing with the HB/OT.
 Richard W. Cummins to General William Clark, February 15, 1831
 See Robin Scott Jensen, Robert J. Woodford, and Steven C. Harper, eds. The Joseph Smith Papers: Revelations and Translations: Manuscript Revelation Books (Facsimile Ed.; Salt Lake City: The Church Historian’s Press, 2009), 53.