In case anyone reads this thread later.. So far, CalyxOS is working out well. The hardest parts were buying a used device for it (uncertainty of getting a version with an unlockable bootloader, and having to avoid all the OLED display problems).
Chiming in with my own experience, as well. The two wrinkles I've encountered:
* SafetyNet doesn't work, as expected, which means no Google Pay. Nothing else I use has been impeded, though.
* Chromecasting doesn't seem to be implemented in MicroG, so no casting content
