I totally agree with your 1st paragraph.
But not all of your 2nd.
Why? Because the laws of physics was thrown out the window in the climatic battle ending. When Grant throws Shizuka's katana upwards, while dangling on a rope in mid-air, supposedly with a battered shoulder, he somehow has the strength of the superhuman he is battling to not only defy the very laws of gravity by throwing the sword straight and true - but to have the impetus to skewer him all the way through, until he is lifted up and pinned to the roof of the balloon ship?!
Then they crash land amongst redwood trees, and don't get a scratch? Really?!
And you stated that the 'banter' between Kane and Brigid is some of the best? Really? Banter?
Is it me, or does the rest of you red-blooded males out there laugh that Kane, after years and years of books, multiple years gone by, that he never even TRIES TO GET LAID! Not even a Captain Kirk type quickie with ANY woman in the series. Gee, how about a story for once on Kane falling for someone? How about love? Then lose her in a dramatic death...at the very least!
The anam chara thing has run its course, oh sooo long ago. Everyone around Kane and Brigid are allowed to find love - or at the very least - get laid. Including old timer Lakesh!
But Kane and Brigid are forbidden? Totally unrealistic, in regards of moving on with their relationship - in ANY meaningful way.
What red-blooded real man fan out there if he were Kane would not - at the very least! - try to talk Frigid Brigid into a little something something on the side? OK, you don't want them to actually fall in love and get married. How about just have sex on the side? Or with at least with the newcomer badss Mexican lady, Rosalia? Or with one of the numerous females ANYWHERE in this series?