Goodness, I wish dates were included on this posts so I'd know if this were an old conversation. But it's the first one here (just dropping by for the second time) that I find intriguing.
Here's my illiterate two cents. SOC is really a continuum of POV tightness that got dropped off in the naughty corner with the writers who came after Joyce. There was a whole bunch of tiresome works -- some of Joyce's included -- that were entirely SOC, boorish, navel-gazing, and lacking bare-chested men with swords. They were often about drug addicts and wanna-be writers (usually in NYC) with plot lines that required a magnifying lens -- or a PhD in literature.
Joyce opened a new vein. He showed another level of POV that pulled language closer to the actual process of the brain. Language, by definition, is a symbolic structure that overlies, obscures the thinking process, not trying to capture it, but trying to make it logical enough to be of any worth socially.
I think all the focus on SOC during/after Joyce just made writers more aware of the range of the tools they already had in their toolboxes. They were already writing very tight third POVs. SOC just took it further, messing with grammar and word choice, punctuation and logic skips.
Rose, when you quoted Roth, you picked a writer who uses SOC with a small paint brush. He jumps to it when he wants to convey that rush of interior tremor that our brains feed us and upon which we build rational thought. But we know it's not; we know it sounds stupid if, when a friend asks us, "How did you decide that?", we regurgitate the actual mental process that brought us to a particular decision
There's a reason we can't stand to listen to folks who actually do describe the actual way their brain works; it's exhausting. We need the filter of reason that the symbolic application words to the process forces.
So most interior character thoughts deserve the filter of structure just to tame the chaos of the brain into something we'd care to read. (When folks say that they read to escape, they are mostly talking about escaping their own minds, although most of them will tell you it's their lives. They're lying; it's their minds.) So giving them a language that strives to mimic what goes on in their minds is torchure. I've tried to read Ulysses three times and don't believe I've progressed past page 33. (The last attempt, on an airplane, maybe six years ago, I hurdled the book down the aisle. It's a big book. No one dared pick it up.)
So what Roth and others -- Mark Gaitskill, Russo come to mind -- have done is use the SOC technique judiciously for those moments in a novel when the writer wants to plunge the reader into the the messy process of the brain, just long enough so the reader recognizes it and when it's over can wipe the sweat of his brow and say, "Yeah, right on, man," but not long enough for the reader's arm to start itching to toss the book down the aisle of the airplane and snatch the latest teen vampire book from his seat mate.
In my writing, I think I slip into the SOC side of the spectrum when I'm already in a tight POV, wanting to give a feel for how a character's mind works, and adding all the necessary nouns and verbs and punctuation would pull away from that or insert a sense of the narrator I don't want. I only do it for a few lines at a time. Maybe that's because I'm focusing more on how one character's interior self plays against another's. It's tough, and I find myself spending hours on the small sections where these sorts of slides take place. But they're also some of my favorites. The more a novel is about one character's process, the more I think SOC would be appropriate.
Maybe here's a quick and dirty yardstick -- when proper structure and punctuation and so forth seem to be tugging and warring with the meat of what you're writing, slipping to the outer edge of tight POV into SOC may jerk the whole thing loose and bring that elusive heat-and-truth bit to the writing.
If anyone is still into this topic, it would be fun to look through our WIP and see where we slide on this continuum and it effects the reader.
Eeegads, I've gone on. Sorry, just haven't read this sort of juicy stuff about technique for awhile.