[Quoth]

Libra since close to release and Libra 2 a bit longer after release. I bought the Nia for the young lady as it's cheap. If she takes a serious notion to write I'll maybe get her a Sage.

It will take me years to read the ebooks on any of my ereaders.

Yes, if your Android phone has a filemanager and OTG host mode a €6 adaptor will let you copy. I've also used the Web browser on an eink (forget the model) to download via WiFi from a Website and many Android phones can be WiFi Hotspots, but download to phone then USB transfer works better (tested with my Android tablet).

Even a Nia has enough space for about 5 years of reading a complete book every 2 or 3 days.
I've about 6,000 on my Sage and estimate of free space suggests 17,000 to 25,000 ebooks possible depending on size, illustrations etc.

My eyes are needing the reading glasses and I find the 7″ to 8″ best. The 6″ is too small and 9.7″ or 10.3″ is too big and heavy.
I do have a 5″ old Sony PRS-350 and replaced now with a newish 4.7″ (no touch, Y-Ben P47L) for leaving in the jacket pocket in case unexpectedly hanging about.