Just caught up on this and it was terrific, certainly my favourite Wardilmore entry in the series. The Nimbus III and Defiant bits were really odd though. I've never been a huge fan of TOS, I think I've seen most of the episodes and about half the movies, but that was a long time ago. I got in to this series as it was just terrifically written and a wonderful story.
I'm aware from reading this board that there are certain references and clever tie-in things that I've missed, but that's always been reading this board after the fact. To me the Nimbus III stuff was okay but felt like it was leading to something in the next book, as part of Jetanian's arc, and I hope that's the case. The Defiant plot was just just a slap in the face though "here's half a story, go find the end somewhere else". It's the first time I've felt that the point of the sub-plot was just to be clever, rather serve the ongoing narrative.
Then again, I've not read Storming Heaven yet so maybe both of those stories will feature plot points that pay off in the books as well in episodes of a very old TV show.