I read The Leopard long ago ....
and from what I remember, I generally agree with the poster. The book has become a classic of Italian literature, and I would highly reccomend it.
What will help a reader is to see the dramatization of the book in the movie with Burt Lancaster and Alain Delon. I watched the Italian version with English subtitles.While it seemed a little strange to hear Lancaster speaking dubbed in Italian, the Italian version is not cut in length, as I believe the English version is.
My advice: watch the movie, read the book; then do it all over again
I just checked with my library via the internet ....
They have The Leopard on dvd so I'm going to watch it again. It was made in 1963; no wonder I couldn't recall much of it. But I do remember how good Burt Lancaster was.