Michael Verschuur insists that his electronic files embodying what he calls the Pure Cambridge Edition of the KJV are a perfect representation of the standard text of the KJV. He means this in a theological sense which I cannot endorse. However, Verschuur has also made the point that, even for people who do not share his theological attachments to the KJV, it still may make sense to talk about a "standard" edition of the KJV for reference purposes.
If we speak of a "standard" KJV in the second sense, I think I must lean toward endorsing the idea that the PCE does embody that standard, though I'd wish to qualify that statement a bit and explain exactly what I mean and don't mean.
When the KJV was published, at least two printings appeared in its first year, 1611, both varying from one another in a variety of ways, especially variations of spelling, punctuation, and italics. In many cases, outright typographical errors existed in both "original" editions. As the years passed, editors of new editions would fix some errors, choose readings from among various previous editions, and introduce new errors of their own. Compared with the relatively subdued state of the text since 1769, the text from 1611 to 1769 was a much more living thing.
In 1769, Benjamin Blayney at Oxford produced an edition of the KJV which did such a good job of cleaning up the text, standardizing spelling, and standardizing the italics that it is only a small exaggeration to say that we have been using the 1769 text ever since. Still, over the following years, from 1769 to about 1900, the text was improved -- mostly in small fixes of Blayney's errors, especially in spelling -- in a over thirty places.
If one's goal in looking for a "standard" KJV is to replicate the 1611 original edition, facsimiles are available. But as far as I can tell, nobody seems to want to go back before Blayney's corrections. So this leaves us various texts after 1769 to work with. How should we choose a standard edition?
Blayney's edition is hard to find -- and is mostly distinguished from 20th-century copies by having two or three dozen mistakes in it -- so it seems to me that going back to Blayney wouldn't be a good option. We may as well stick to the KJV that was mass-produced in the 20th century, and what better text to use than that of Cambridge University?
At least at first glance, working from Norton, it would appear that the PCE either exactly or almost exactly matches Norton's conception of the "standard text", and the PCE has the added legal advantage of having been produced prior to 1928, as works after that date may in some cases be under copyright in the United States.
What other electronic editions of the KJV exist? At av1611.com, there is an electronic edition by Brandon Staggs, which Staggs claims to have created using a 1920 Cambridge Cameo Bible as his exemplar. I have used an electronic tool ("wdiff", after some prep work) to compare the Staggs text to the PCE text, and there are only two differences. One difference, which occurs repeatedly, is whether to interpret the S at the end of the word "LORD" (which generally appears in small caps in printed Bibles) as an uppercase S or lowercase s. Staggs treats these S's as uppercase; the PCE treats them as lowercase. This is something of a judgment call, but I believe that linguistic logic favors the lowercase interpretation, and a careful examination of a facsimile of Blayney leads me in the same direction.
The second distinction between the Staggs and Verschuur texts are at 2 John 2:23, where the PCE, but not Staggs, brackets the word "but" in 1 John 2:23. The verse is somewhat unusual, because the second half of the verse is in italics: but he that acknowledgeth the Son hath the Father also. The words are italicized because they are of doubtful authority -- most Greek manuscripts don't have them, but some do. However, even this doesn't fully describe the situation. The fact is, the texts that have the longer reading have he that acknowledgeth the Son hath the father also, but they do not have a Greek equivalent of the word but -- that word is added by the translators for clarity. Ordinarily, in the KJV the procedure is to italicize words added for clarity, but since the second half of the sentence is already italicized, this leaves the translators no way to indicate what they have done with "but". The solution that some printings of the KJV have used is to use brackets here. Others have not.
Unless and until some electronic editions appears that has some better claim than the PCE to representing a "standard" text of the KJV, I think I could easily recommend to anyone that they use the PCE as their KJV.
Still, this doesn't mean that the PCE reflects the best possible KJV text in every place. I know of three places in the PCE text where I would argue that the PCE doesn't quite get it right.
In the Song of Songs, the KJV's usual policy dictates that the name "Ammi-nadib" should be hyphenated, because it consists of two words in Hebrew. This policy is followed in Blayney's 1769 folio, and in this 1900 printing by Cambridge. The PCE, however, eliminates the hyphen and writes "Amminadib", as if the name were one Hebrew word.
In Joel 2:24, many editions -- perhaps most -- have fats, an archaic spelling of the word vats. Verschuur's PCE text follows this spelling. However, not all KJV's do. Several editions, including this printing by the American Bible Society, uses the clearer spelling "vats". Given that no one today spells the word vat with an f, it seems to me that choosing the older spelling here has no real advantages.
In James 2:16, in "be ye warmed", the word "ye" is wrongly italicized in the PCE and many editions that follow Blayney. However, this 1738 printing does not exhibit this mistake.