I read somewhere that FSF said that he always felt a little awkward in the East.

I disagree that Nick is being ironic. Nick doesn't seem to be the least bit ironic anywhere in the novel. I say this having taught it for 15 years at college level. I've gone deep into this novel with hundreds of students.

Look at the beginning, when he's writing in retrospect, looking back over the summer in New York. He says that what he saw there made him want to return to the Midwest. He's fed up with the moral carelessness of the people he found in the East: 'Conduct may be founded on the hard rock or the wet marches, but after a certain point I don't care what it's founded on. When I came back from the East last autumn I felt that I wanted the world to be in uniform and at a sort of moral attention forever....' That may be moral superiority, but I don't think it's irony.

Nick is somewhat self-aware. He acknowledges that he can be a bit of a snob (Gatsby represented everything for which he had 'an unaffected scorn') and also that everyone prides himself on one virtue - and his is honesty. So yes, he may be morally superior, but given the company he was keeping, he had a right to be. I think he was genuinely shocked by Tom and Daisy's moral carelessness, their 'secret society' of cynicism that could smash up people and things and then move on, leaving the mess for others to clean up.

There seems to be some genuine Midwestern moralizing going on in the novel, and easterners (or those who adapt to the east), don't come off very well.

But GK dissed The Great Gatsby not so very long ago, saying that it was embarrassing to hear it read aloud because it's not a very good novel after all.

I disagree if we can say that a great novel in any culture is one that puts its finger on something that members of that culture can identify with, can say - from generation to generation - 'Yes, that's true about us. That's how we are.' Shakespeare does that with human beings, period. That's why he is loved in pretty much every culture. Fitzgerald does it in TGG with the American tendency always to be thinking that tomorrow will bring something better, to hurry through today 'in a continually disappointed anticipation' of what will come tomorrow, of the 'orgastic future that year by year recedes before us.' We keep reaching out for the American dream, and (like so many things in the novel) it is beyond the reach of our hands. But still we 'run faster, stretch out our arms further...'

Having lived abroad for some 18 years perhaps I can see more clearly than I could have had I stayed in the US, that Fitzgerald really touched something true about us Americans: we are often so preoccupied with 'one day' when we have acquired the lifestyle (or weight or 'stuff') that we think will make us happy, that we don't know how to be in the moment and enjoy what is right in front of us.

I think that - and the flawless writing - makes the book a classic.

The thing that puzzles me about the quote you mention - that ALL of them were 'unadaptable' to eastern life - is that it doesn't seem to be true. He describes the bored, swollen cities, and gives a strange image of a drunken woman in evening dress being carried 'home' to the wrong house - and nobody cares. It's that bored, cynical carelessness about any kind of standards that seems to typify the East for Nick. (Consider his reaction to Daisy's account of Tom's affairs: that she should take her baby and leave the house; that he - Nick - feels like calling a policeman.) Tom and Daisy seem to have adapted perfectly to the East, to suit that environment down to the ground. Because of Tom and Daisy, a woman and two men die - and they don't care. So I don't see how Tom and Daisy are 'unadaptable' to a part of the world that is 'bored' and morally careless, a valley of ashes.

It's a complex novel and not as airily dismissed as I think GK does dismiss it. But hey - a man who can read 'The Raven' (including rhymes like 'window lattice/what thereat is' and 'though thy crest be shorn and shaven/ Thou art sure no craven...raven') and not snort in derision makes me wonder about his literary training.