God, I love this pair. Logan's dominance is stunning, and his need for Jin moreso. Watching them grow together through all that they've endured was a treasure. And ye gods, did this one run them through the wringer. It was a touch slow in the early parts when their history and laws were being repeated in conversation (necessary if you haven't read the last two in a while or don't read the books in order, but Gods! why would you do that??), but once that was over and we get to the sepat, it was brutal and so, SOOO good. I couldn't put it down. And though I realized what was happening not long before the big reveal, the ending drove me to tears when it was all over and decisions were being made. (Vague enough?) The relationship building, the power structures, Jin's power, it was all just phenomenal. 
 (view spoiler)[But I still didn't get to see kids, Mary. I want to see their kids! *harumph* (hide spoiler)] 
 I really hope that this isn't the end of this universe, though it may be the end of Jin & Logan's story. (Or mostly!) There's a lot of world-building that's been built up that I would love to see continue. Changes are coming, and there have to be some who would push back on that. And we can revisit Jin & Logan that way. =)