If pressed, I would say that I prefer novels with unity of time, place and action. And not too many characters. Especially, not too many characters. As a teenager, I think I made it through to the end of Anna Karenina but I'm pretty sure I didn't finish War and Peace. Right now, I have stalled on a 20th century War and Peace, Vasily Grossman's Life and Fate. I keep forgetting who is who - it seems this is expected, because there is a crib sheet of names. It's a pity: I admire Grossman's writing, I think Everything Flows and his war journalism are terrific. But Life and Fate is too much of a cognitive challenge.
Adiche's book is spread panoramically across three continents, in Nigeria, the USA and England - a bonus for publishers I'm sure - and it has a large cast of characters with names which to me are unfamiliar - just like Tolstoy's - and it is spread over decades. But because it has a fleshed-out core couple at the heart of it - Ifemelu and Obinze - it doesn't fall apart into a series of scenes. There are scenes but they are managed in such a way that they rarely seem disconnected. In other words, Adiche maintains a strong narrative thread. There is a story, a romance, developed over 477 pages.
There is also a strong thread of social commentary, spun out from the hub of Race. It's often funny, acid but never hectoring. It picks up on the significance of everyday, taken-for-granted acts and omissions, making us see them afresh. It's very well done.
Ifemelu is a complex character - insecure, abrasive, courageous, very clever and very demanding. In the end, the man she wants only gets her when he puts out to the maximum - nothing less will do (I was reminded of Pretty Woman).