So I've finally read it, and I'm not sure what I think. I know that I disliked the first half, with its constant string of repetative jokes (and when I say "constant," I really mean it: page after page, paragraph after paragraph, joke upon joke upon joke).
Gradually, however, I became aware of "the trend," and therefore I started to "get it." Every one of the huge number of characters is a critical piece of the novel's fine-tuned equipment, like the 34 miniscule parts of Orr's tiny valves. They're like parts of one of those Rube Goldberg machines: each character is ridiculous, but they fit together and spin around and perform their stereotypical actions until -- at the end -- Yossarian is popped out with a new, honest, and strangely noble purpose at the end.
I also noticed that, about halfway through, the novel was getting darker. From the first uneasy hints about Snowden's death in the plane, to Milo's bombing of his own base in order to make a profit, to Kid Sampson's comical but gruesome death ("Kid Sampson had rained all over. Those who spied drops of him on their limbs or torsos drew back with terror and revulsion..."), to Yossarian's gut-wrenching, helpless walk through "The Eternal City," and ending with a real, final, blow-by-blow description of Snowden's slow death from a piece of shrapnel that literally burst his entrails into the casing of his flak jacket...
Wow. My skin crawled. By sickening me with silliness and then, gently, leading me into some of the most grotesque and hopeless fiction I've ever read, "Catch-22" did something that most books can't do: it UPSET me. It didn't necessarily ENTERTAIN me or EDUCATE me, but it got under my skin and made me hurt, mentally. As for its comparisons to Gravity's Rainbow...I can certainly see that, but whereas Gravity's Rainbow is paranoid yet hopeful, Catch-22 is more cynical and relentlessly pessimistic: the characters know EXACTLY who is out to get them, and they know EXACTLY how it will be done, and there's no way of stopping it.
I think the book is often messy and confused, and too wrapped up in its cleverness for its own good. But at other times Joseph Heller's games made me laugh in outright delight; other than Nately's Whore's outrageous homicidal antics, which had me stifling my laughter in my little cubicle at work, my favourite moment was understated, and one that you needed to read closely to understand:
'Hungry Joe was killed.'
'God, no! On a mission?'
'He died in his sleep while having a dream. They found a cat on his face.'