I can't say that The Other Queen is my favorite Gregory book (that honor still belongs to The Constant Princess) or even close, but I did enjoy it.
I'm not sure where Gregory comes down on Mary, Queen of Scots. Her portrayal of Marie Stuart is not particularly sympathetic, but neither is it completely unsympathetic. Though she is one of the three narrators of The Other Queen (and her story is the basis for the novel), Mary is not the star of the novel. The other two narrators--George Talbot, the Earl of Shrewsbury, and his wife Bess--are much more significant. After finishing The Other Queen, I have no strong feelings about Mary beyond confusion about her relationship with Bothwell.
What was particularly interesting to me while reading The Other Queen was Gregory's take on William Cecil. It is completely at odds with my impression of Cecil based on Fiona Buckley's Ursula Blanchard mysteries (the first of which is To Shield the Queen). Buckley's opinion of Cecil, while not glowing, is decidedly more positive than Gregory's. This makes me want to delve more into the period to get a better sense of Cecil's character.
I'm not going to wild release The Other Queen because I'm sure that my mom will want to read it.
Edited to add:
I forgot that I wanted to share the opening of the novel:
Every woman should marry for her own advantage since her husband will represent her, as visible as her front door for the rest of his life. If she chooses a wastrel she will be avoided by all her neighbors as a poor woman; catch a duke and she will be Your Grace, and everyone will be her friend. She can be pious, she can be learned, she can be willing and wise and beautiful, but is she is married to a fool she will be "the poor Mrs. Fool" until the day he dies. (1)That first paragraph is both a taste of Bess and something that made me think of how times have changed and how they've stayed the same.