Mavis Gallant being the author, I knew the writing would be immaculate, so there was no question of the book being an unreadable mess. I found the narrative was not very interesting and hard to follow, but the characters and situations were often enough to keep me reading. This reminded me of her nearly interminable short stories, which are masterful but I find I need to be in a certain state to really enter and enjoy them.
I was frustrated at times by my inability to focus and follow but in the end I'll chalk that up to masterful construction - life isn't neat, the processes of thought aren't always clean or logical, and other people are almost always frustrating to deal with and filled with inconsistencies and stubborn courses of action. That, or the book was not exactly what I enjoy, or, finally, my mind is rapidly falling apart and my ability to read fiction is disappearing.
So, yeah, this novel was worth the (admittedly long) time I spent reading it, and I did enjoy it, and it exceeded or escaped my expectations.