There is nothing in the e-Ink tablet space that can render high resolution PDFs and image files?
It's been a few years since I tried a e-Ink device, it was pretty mediocre back then. However, I would have thought that by now e-Ink devices would have no issues with performance.
Onyx Boox makes pretty nice devices that (from what I've read in reviews) have no problem rendering pdfs or running most android apps you chuck at them.
Cons: using demanding apps drains battery at the rate you'd expect of a tablet, not a dumb e-reader, plus they're expensive.
Why have I not heard of RLCD before :/ I recently bought an Onyx Boox 13" reader, and while I like it a lot, it's still just black and white, but also has some ghosting.