For reading books, I'd rather go for an Android based device that features a more potent reader app that allows you to set bookmarks and to more easily jump around in big books. It works very well for reading papers and well structured books that don't ask you to look back x pages all the time.
I agree. I’m waiting on a Boox Lumi at the moment. I read PDFs on my reMarkable primarily because other formats, specifically e-pub, aren’t that great on it. As strictly a PDF reader the reMarkable is good (albeit overpriced for just reading PDFs.)
The nice thing about android is that you can also get a kindle app. I know the parent is looking specifically for PDF support, but it’s nice to have solid kindle, PDF, and e-pub support on a single device.
Fair enough - the page change UX is a little clunky (and anything requiring changing screens many times on e-ink will be clunky). I read papers a lot more than I do textbooks. For fiction, the successive page turns are fine.