One of the reasons I think it's important to teach pre-1800 texts is that it takes practice to tease out long sentences if all you've been reading is Chuck Palahniuk. Long, well-crafted sentences are more likely to offer examples of subtle, careful rhetoric. I've said before that I'm really attracted to dudes who know how to use a subordinate clause—not because I like Ivy-League dudes who are way into Milton, but because it's a sign that the mind is supple and sees in more colors than black and white.
Late James is the best prose for reading aloud. Saying one of his interminable sentences, the voice must drop pitch every time he interrupts his syntax with periphrasis, and drop again when periphrasis interrupts periphrasis, and again, and then step the pitch up, like climbing stairs in the dark, until the original tone concludes the sentence. One's larynx could write a doctoral dissertation on James's syntax.
Sandwiched between these two statements are numerous complaints about Twitter, text-messaging, and how they rob one of the ability to discern the subtleties of long sentences generally and late James specifically. When AWB or Hall praises complex sentences, they do so because such sentences require an ear for subtlety the dessicated literalism of a pay-per-word culture deafens one to, i.e. you wouldn't catch James resorting to ALL CAPS for emphasis, because his readers could tease the emphasis from contextual clues.
Only as the transcription guide [.pdf] to "Dear Henry James" attests, James frequently employed the nineteenth century equivalent of ALL CAPS: the underline. When his letters are transcribed, his underlining is preserved using ALL CAPS or italics for single underlines, ALL CAPS for double, UNDERLINED ALL CAPS triple, &c.
So James' famous exhortation to Edith Wharton usually looks like this: "DO NEW YORK!" The ALL CAPS is understandable there, as it marks the exhortatory nature of an exhortation; however, James regularly underlined words which are already emphatic, such as the emphatic do: "DO be so far as possible his Lady Ripon." Happens quite a lot. Perhaps this double emphasis is conventional, and that in the course of one of his long, winding late-period sentences he would include no twitter-markers. Here's his 1907 account of a car accident (from a letter to Wharton):
Apropos of smashes, two or three days after we had crossed the level crossing of Caianello, near Caserta, SEVEN Neapolitan "smarts" were ALL killed dead—and this by no coming of the train, but simply by furious reckless driving and a deviation, a SLIP, that dashed them against a rock and made an instant end. The Italian driving is CRAPULOUS, and the roads mostly not good enough.
I don't think anyone would accuse Wharton of being an unsubtle reader, yet James writes as if his emphasis couldn't be gleaned from contextual clues. All of which leads me to believe that such DEVIATIONS and SLIPS might not represent the DECLINE of comprehension so much as the continuation of a traditional emotional register of no small communicative import, INDEPENDENT of standards of literacy; such that the comprehension of READERS should not be thought the worse for merely reading what AUTHORS want to express with a VEHEMENCE unrelated to understandability.