[fishface]

AFAIK two vital things need to happen before e-ink research paper readers can be feasible:

1. Large form factor (10' or bigger). PDFs generally break when reflowed, and a lot of papers and textbooks rely on specific placements of figures and equations. e-ink is slow to refresh and PDFs are slow to render all contributing to a no-go for scrolling.

2. Pen-based PDF Annotation support. You need to be able to use a pen to ink onto the PDF like using PDF Revu or PDF Annotator or Acrobat. Circle a symbol, highlight, etc. My favourite thing is to underline specific terms in equations and link back to their previous forms in prior lines of the derivation, and to annotate graphs to highlight the regions I should pay attention to. Can't do any of this with text notes.

3. Decent processing power to render equations, graphs and such.

Currently nothing exists that supports this, not because the tech is unavailable, but because the combined cost of all these things is a lot (over $1k for sure) and apparently the bean counters have determined that it does not look like the market will support it (even though, you, me, and every academic I know will not even hesitate at a $1k to $2k price point because it's just that useful to us... but unfortunately we are a small fraction of the population). So it's an LCD tabletPC for now, for me.

PS I had high hopes for the Boox M90 but it's been having technical problems and I've looked at the inking experience and not been impressed.