It's an important book but not a particularly good one.
As a novel I'd give it B-.
Winston is dull, Julia a fantasy figure, O'Brien a copy of Dostoevsky's Grand Inquisitor.
But of course it's the ideas that count.
Which are mostly wrong.
Orwell prophesies North Korea. The rest of the world has gone down a very different path.
He assumes the inner party will be made up of monkish fanatics- like O'Brien. But such people are terribly rare. Stamping on the human face forever is a minority pastime. So that's one mistake.
Another is to dismiss the proletariat as a lumpish lumpen mass. No class is as homogenous as Orwell needs it to be for his society to work.
Finally, societies as crummy as Oceania collapse under the weight of their own crumminess. People- at every level- want more. North Korea only survives because China props it up.
You can crush individuals- but a whole society? a whole world?
Let's just say it hasn't been done yet.
The human spirit is resilient, tenacious. Like a weed.