8 years ago
  Logitech (Keyboard)
  Mint (older version)
  Works perfectly
What works:

Everything (except for the ability to unify or re-pair) works perfectly right out of the box.
All keys work as I expect, including media and volume.
The FN modifier selects the pictographs on the F keys, all of which work about as I would expect, though many of them have redundancies in default shortcuts.

What doesn't work:

The Logitech SetPoint software does not support Linux. SetPoint is the only way to re-pair their unifying devices.

What was done to make it work:

Unifying and re-pairing devices through SetPoint on a supported operating system (presumably) change the firmware.
Changes in device pairs are recognized by Linux