Most of the mistakes people are pointing out which are new to the collector's editions are publishing errors, not textual ones. Exceptions, such as the missing section in Book 3, seem largely to remain isolated exceptions. I bought the Mega-deal, and do not recall any commitment made by Mongoose that the books would not be published as previously written (except Book 1, the new art, and the new map). Therefore, I do not expect such. Most all "collector's editions" are reprints. Special, yes, but still only reprints; no more, not less. That reality forms the baseline for my expectations of Mongoose for those editions (just as it forms the basis of my expectations of any book publisher that publishes a "collector's edition").
There is little realistic point to reviewing a pre-printing .PDF of the "final" book immediately prior to printing. One, that will not actually capture any of the publishing and binding errors that have formed the greatest majority of complaints I have seen so far regarding the collector editions. Two, if the .PDF is of the "final" book, then it is too late for an "independent reviewer" to actually catch anything that can be fixed prior to the books being printed (such is the nature of a "final"; if it is issued earlier than before the book being printed, then such a .PDF would be, by definition, not a "final" and therefore errors still might creep in between the time the .PDF is reviewed and the book printed). I have worked for a printing company in the past, and so do not have any illusions about how this process typically works.
Frank the Wanderer