Information about the deficiencies or merits of a given work of fiction can come from a number of sources, I am sure that you must agree.
As I'm sure you've noticed of late, we have vastly different opinions on a number of matters. In view of that, please refrain in future from presuming to be "sure" of what I agree with.
From curiosity one can attempt to read the book because it was made available on the library or bookstore shelf. One can physically pick up the book and scan through it to gain an impression of content and writing style. One can also take into consideration editorial and reader reviews to judge whether the purchase of the book is warranted.
I find it interesting that you have avoided Lisa's question ("...have you read the book, Margarita?") and also skirted my follow-up. Further, precisely as I suggested, all of the methods of analysis you propose involve reading some portion of the book, or at the very least gleaning information from those who have read it in its entirety. If you give a book a try and didn't like it, fine -- but again, it's only fair to say as much so that others can make informed decisions. If on the other hand your opinions of "a given work of fiction" are derived from others' analyses, those sources deserve credit.
But let's quit pretending we're talking hypothetically. This thread concerns
Curse of the Romanovs and Lisa's question still stands: Have you read the book -- or any portion thereof?