I have spent so much of my life trying to be critical (in both senses of the term) of Jane Eyre and, more specifically, Edward Fairfax Rochester and it remains intriguing to me that he's still such a compelling character in the text. That you can take them apart outside of the book(s) and then come back and see both of them in the book and it's just BAM.

Anyway, this book is wildly successful at doing what it sets out to do--taking the structure and experience of Jane Eyre rather than the specific plot beats--and transforming it into a modern narrative.

There were two things that stood out for me in how Edwards handled them.

The first is that she understands that Rochester has to screw up badly enough that you understand why Jane leaves and not so badly that you think she's wasting her time going back. So many people try to walk this line and what Edwards gets deeply is that's not *just* about Rochester; it's about what Jane can accept. Making Jane a foster kid gives Edwards the space to unpack Jane's reaction as reasonable given her background and the right thing to do for her without making Rosen evil. It was a really good call.
The second thing was her pitch perfect evocation of St. John Rivers as a career minded early academic trying to convince Jane to think his way and play his game because they're convenient for each other. 
This was one of the few books where I reacted to both the Rochester and the Rivers characters the way I did in Bronte's original and the absolute obnoxious condescension from Rivers that highlights how Rochester sees Jane as a person was brought into this version brilliantly.

This is not the retelling that hews closest to the original, but it's the one that captures the feel of the original for me.