Well, I finished it. And I despised every moment of it, from the writing to the characters. Maybe I just don't understand or appreciate a writing style such as Styron's, but I just found it incredibly tedious and tiresome to wade through all of Stingo's incessant (and lust-fueled) rambling. I hated him and in turn ended up absolutely hating Sophie and Nathan. When you reach the climatic point in the novel and you don't feel even the slightest twinge of anything other than, thank god this means it is almost over, then you know that you should just call it a day and admit failure.
So, yes. Sophie's Choice. Huge, gigantic and miserable no go for me.