Personally I never thought the Borg were that great an idea. There was very little you could do with them story-wise; they were more a force of nature than a personified antagonist. That's why the series shifted to telling stories about liberated drones, and introduced the Queen to give them a face and voice. The original concept was just too limited. If you want big space battles and action, then sure, you can use them for that, which is why they're still around in ST:O. But as a source of story they're problematical. So they don't work as well in prose.
Recall that before the post-NEM TNG novels, the Borg were rarely seen in Trek Lit. The Borg were introduced on TV in 1989; Resistance and Before Dishonor were published in 2007. In between those, the only novels that really featured the Borg in a central role were Vendetta, The Return, and Engines of Destiny. There were a couple of stories about finding Borg ruins (Mission: Gamma -- Lesser Evil and Corps of Engineers: The Light), and eleven out of the total 211 stories in Strange New Worlds were Borg-related. Plus they made a cameo in The Siege and were implicitly referenced in Probe. That's three featured roles and a few sidebars in eighteen years. That's not a lot of prose. And there are reasons for that.
I must admit that I find your disinterest in the Borg a bit off putting since you wrote a pretty good Borg-centric novel. That being said, I think the Borg work best in small doses and in a way precisely for some of the reasons you said. They are a force of nature. And I like seeing our heroes deal with something that unstoppable. A lot about the Trek characters is/can be revealed in every encounter they have with a foe like the Borg.
As for the Borg themselves I still find them pretty cool. I like the aesthetic. I like how the species is composed of some many other species, all adding their knowledge and skills to the whole of the collective. The anti-Federation Federation aspect of the Borg still makes them an interesting adversary.