For the first ~150-200 pages of The Other Boleyn Girl, it was a solid 3-stars. Then it meandered down to 2-stars. By page 350 it was a 1-star. The end was compelling enough to bump it back up to 2-stars. The Other Boleyn Girl can be fun, trashy entertainment. The factual basis is obviously tenuous at best (they got most of the names right!), but why focus on facts when you can have crazy drama? All this works out to what could be a nice guilty-pleasure read at first, but quickly devolves into repetitiveness and monotony. A good third of this book could be edited out or at least shaved down to be more succinct. It became such a chore to read.
On a more technical/less personal enjoyment level - it's not much. The writing is atrocious, especially the dialogue. Despite its considerable length and the scale of the real-life events the narrative recounts, it's very simplistic. And the characterization is practically non-existent. Everyone's shockingly one-dimensional, despite the fact that these are all real people who have not only existed in real life but have been meticulously studied and biographed for centuries. Gregory didn't have to make these characters from scratch, she just had to write a story around the already fully formed historical figures, yet all the characters, including Anne Boleyn, were flat. The characterization relied very heavily on a Madonna/Whore dynamic between Mary and Anne. Mary is the 'best of the Boelyns' and the innocent victim despite everything, and Anne is the conniving whore relying on her looks and cunning to lure men. I recognize that an attempt is made to more fully form these characters and break out of the Madonna/Whore dynamic. And that Gregory at some points tried to present Mary and Anne as some kind of two-halves-a-whole duo. But Gregory is just not skilled enough a writer to believably pull that off.
I didn't think I could enjoy some Tudor England drama this little.