Which is worse?
Finding a book you love and then hating everything else you try by that author, or
Reading a completely disappointing book by an author that you love?
I, thankfully, have never had the experience of finding a book I love and then hating everything else an author has written. I have occasionally been disappointed in a novel by an author I love. John Irving comes to mind. I've enjoyed every book of his I've read, but was never able to get through Until I Find You. When it was first published, I had to run right out and purchse a hardcover copy. This could be a case of "right book, wrong time", so I'll give it another shot at some point...but at 800 pages, it won't be right away!
Additionally, some authors seem to have different styles of books. I love Margaret Atwood's 'female relationship' books, like Cat's Eye and The Robber Bride more than her 'science fiction, dystopian' books like The Handmaid's Tale.