Alright,
took the Opus for a few spins last night.
I am noting down my experiences in a German topic which has already grown to be a bit longish. Duplicating it here would be too time-consuming so let me summarise real quick:
- I'm happy with the Opus so far!

- After transferring some files to the device before starting to use it, it froze up completely for me. Had to "hard-reset" it via the backside reset button. No freezes since though, maybe some freak incident
- The rendered books and fonts looks awesome, I'm sold on eInk despite the slight "recycling-paper" background feel
- After almost 30 years of being a paper book-lover, it does need some adaptation on my part to use the device, but I guess that's normal. It certainly feels a little like a "paradigm shift" to me, but not in a negative way