To Dave-in-Decatur and CalS,
The blog posts are intended to be an objective description of my experience, so that others can decide for themselves whether the effort is worth it to them - and perhaps avoid a few pitfalls. And to give people a little real world data to estimate the effort required - something I couldn't find online when I started this.
It was never intended as a sell job for OneNote.
For me, Dark Mode is a deal breaker. And I assume it's pretty important to anyone else reading this thread. I have concluded that Dark Mode on Windows is unlikely to appear anytime soon - in particular, before my hacked Evernote executable stops working. I could be wrong. But, like I said, it's a deal breaker for me. I cannot use a retina-burn-white background, and I decided to get it over with while my hacked version is still working and I had some free time to work on it.
And, so far, I'm quite happy with OneNote. It feels comfortable already. And I can use my SPro and pen as a tablet - even record voice sync'ed to the content. It has replaced Livescribe for me. For me, it was worth the time I invested. Others may make different tradeoffs. The blog posts were intended to help people make that tradeoff.