I used to think it was a good book.
Not so much any more. I view it now as something of a leftist tome.
I also suspected that Harper Lee either didn't write it, or had some serious help (perhaps from Truman Capote).
The primary reason is that if it was "that good", it almost certainly represents the product of a talent that should have produced "more" in the author's lifetime.
And after that, she wrote... practically nothing.
The movie was OK, however.