Decent with a lot of hit and miss. But mostly hit.
The characterization of the Horta was fantastic. It was so good that I hope this novel is used as the basis for any new Horta characters going forward. I had this vision of a post-script where Slider Dan arrives at Starfleet Academy and admissions mixes up his application and he's then called Cadet Dan Slider.
Liked the development of Vesbius as well.
The rest was a bit cookie-cutter, especially the relationship between Kirk and the love interest "of the week." Same for the villains.