I've recently finished working through looking at variants (in the four Gospels) between Scrivener's 1881 Greek New Testament (ostensibly the Greek text behind the Authorised Version, with variants from the Greek text behind the Revised Version in bold) and the NA27.

In what will come as a surprise to no one who has read of variants between the various TR editions (loosely 'Byzantine') and the NA/UBS editions, I make note of the following sorts of general differences:

• Scrivener's TR seems to be the more harmonizing of the two in accounts among the synoptics.
• Scrivener's TR adds specificity where NA/UBS assumes things. For example, in Jn 20.29, Scrivener's TR explicitly adds Θωμᾶ (Thomas) while NA27 assumes it.
• Also, when editions are different, Scrivener's TR will tend to make pronoun references explicit by including the name (likely with article) instead of the pronoun. This is seen when things like NA/UBS have "and he answered and said to them" where Scrivener will have "and Jesus [with article] answered and said to them" (sorry, no easy refs at hand).
• When different, Scrivener's TR routinely adds an article to personal name (though not neccesarily place names) where NA/UBS lack the article.
• John has far fewer differences (and they're far easier to reconcile) than the synoptics do.
• Differences of case and number (but same word)
• Differences of orthography
• Bona-fide, different-word variants. Though likely to Bart Ehrman's dismay, they are not earth-shattering or of the nature to severely change the meaning of the text in the vast majority of instances. And where they are, they are well-documented in the apparatus and commentaries.

I post this anecdotal list not to present some new, gasp-inducing information; rather it is simply to record it for myself. Writing helps me remember things, which is why you've no doubt noticed that when I discuss things like this, many times I simply restate the obvious or conventional wisdom in different words.

I will say, however, that working through each and every variation (thinking about which parts of the two editions are the same, and which parts are different) underscored the sorts of variations one finds in the Gospels of these two editions. And that, of course, will help me in the future when examining variants of all stripes. "Oh yeah, like the diffs we find in the gospels of NA and TR editions". Note that most Bible Software support textual comparisons for this sort of purpose. Logos has a video showing the feature used with English versions (go to around 1:14 for the specific feature), but it works with any language.

At least for me, it's one thing to read an abstract, digested version of information (such as you'd find in an a book on textual criticism or the Byz/NA debate) and quite another thing to actually work through primary data and come to my own conclusions. The above anecdotal notes are nothing different than an introductory tome on the matter would make note of; but for me, it sticks in my head better (with examples more readily in mind) because I actually worked thorugh it.

I will also say that as I go through Acts, at least at present, the variations are of a different character than the gospels.