Device to save Highlights (and maybe Annotations) for the future

[helixpteron]

Hello,

I’m not new to reading this forum for my earlier devices, but it’s my first post asking a question.
Thank's for your for your expertise, also now and in the future .

I guess all of you pick up an old paperback from time to time, only to find your old highlights. This brings me right back to the moment reading the book.
I think this can be a tremendous help in processing the content you have read years ago.
At least I do, and I wish I had that in electronic form. In electronic form it helps you do quotations tremendously.

So far I had different Nooks which where mostly rooted and a Tolino HD3 which broke before I was successful rooting it. I wasn’t so keen, because the Tolino saves your highlight into a .txt anyway, which I found great.
I did like the open Android on the Nooks, but didn’t use it to it’s full potential. At the time annotations weren’t priority.
My father has a Kobo Glo HD, so I also know a bit about Kobos.
As desktop software I use Calibre 2.75 on OS-X and I have installed the plugins to read and write the Kobo metadata, as well as the KoboExtended and KoboUtilities.

You can see - I am planning to buy the Kobo Aura One, but I am also thinking about what would be the best option in terms of some specific requirements:

I think it is nice to have device sync for reading positions, bookmarks and highlights now, but to me it is much more important having all that saved for the more distant future.
Therefor I could also buy an Onyx Boox 81 to have an open system. So far this didn’t seen to help much in terms of preserving annotations on epubs, but maybe
I should switch to using pdfs and annotate them directly. If that works fine - it would be worth the tradeoff to the nicer screen on the Aura One. What do you think ?

So finally my QUESTION :

Do you think I will be happy with the Aura One with KoReader in terms of making and preserving highlights, or should I go for an Onyx Boox to achieve that ?
I know that the Aura One will have the better screen and lighting by far.
I read mostly epub and the occasional pdf, so saving highlights on both formats would be ideal.

Thanks and sorry for the long text, Rob.