Same thoughts on Naked Lunch - one of the few books I didn't slog through because I wasn't enjoying it.
Gravity's Rainbow - yes, it's difficult. And I read it after The Crying of Lot 49, which was a very enjoyable read.
It also reminds me of Ulysses. Joyce's short stories are accessible and "easy" (I don't mean that as a pejorative, but relative). I was reading Ulysses while traveling abroad and I ran into a Dubliner (we weren't in Ireland). who asked me why I would read that book. It's been about 15 years since I read it and I can't recall much of the "plot". Yet, I can recall the major points of Hemingway, Tom Robbins, Vonnegut, etc. books that I read 20+ years ago in my teens - there's an economy to that writing.
Don't even get me started on David Foster Wallace's Infinite Jest - intimidating and remarkable at the same time.
Murakami is interesting - I read Hard-Boiled Wonderland last year after not having read any Murakami in maybe 10 or so years. I actually picked up - and became familiar w/ him through - Kafka on the Shore because of a book review clipping my mother sent me. The review mentioned Prince and, of course, "Kafka" in the title hooked me. I've read that people have read that book dozens of times to unwrap everything. I like Murakami, but....ain't nobody got time for that.