I am pleased to see that an Amazon reviewer ably summed up exactly my feelings about the book, so I will quote it below.
The short version -- I still plan to read Middlesex, there were nice moments in here, the guy can clearly write, but in the end, I didn't care about the characters, and I didn't believe they cared about each other. Also, despite all the descriptions of sex, in detail, I found none of said sex erotic or even affectionate. And a fair bit of of it was mildly misogynistic to boot. These characters are living in an incredibly impoverished and self-centered emotional world, and yes, they're in their early 20s, but even so.
"It may be an effect of the novel's overall tone and voice; Eugenides assumes a chipper and distantly objective voice in dissecting his characters' inner voices and emotional turmoil, mental lives and activities. His cool, shrink-like/God-like stance however keeps us at a distance and thus from empathizing with their travails despite at times sympathetic portrayals; instead of being drawn into the felt hurts and rawness of their dilemmas, there was a constant underlying thrum reminding me of who they were in the times they lived in (early 1980s) i.e. privileged and self-absorbed college graduates without especially great financial concerns or obligations other than to themselves and what they felt entitled to. There was a diffuse sense of their sophomoric attitudes, jejune concerns and overall busy-ness in tending to themselves and nursing their mental images of each other, such that when reality intruded in a big way, they were all hugely unmatched. It was hard to feel like I actually cared very much what happened to these people one way or another, unlike the protagonist in Packer's novel (as irritating as she was in her own way).
I'd even go so far as to say that The Marriage Plot is a misnomer; Eugenides claimed in a radio interview that he was attempting to traffic in the tropes found in Victorian novels but as I see it, there was something flippant and even subtly snide and derisive in his treatment and approach to his characters playing at adulthood. The notion of marriage and its crucial implications on the economic and social status for women in the past certainly did not apply in the novel's setting; by contrast, what we have here is merely a mildly convoluted case of trite boy-girl relations heightened only by dint of the microscopic lens the author put them under. To that end, perhaps an alternative title to the novel might more aptly reference the knots and entanglements they all twist themselves into rather than any notion of marriage at all." -- JSC Siow
(I've moved on to a book on John Robshaw and block-printing for my next read -- also somewhat self-centered, but at least blatantly so. And I'm learning things about technique, so that's good.)