Fully agree with post #6 above.
I have gone through the following units:
1. Nook Color (original with 7 lcd inch screen) tablet (retired)
2. Kindle DXG (9.7 inch screen) e-ink reader (retired)
3. Nook HD+ (8.9 inch lcd screen ) tablet (limited use)
4. LG gPad 8.3/Verizon (8.3 inch lcd screen) tablet (current)
5. Powerbook 840 Inkpad (8 inch screen) e-ink reader (current)
I would fall under the "he reads a ton of books" category. My goal was to find a technology and screen size that would be the easiest to use, would produce minimum eye strain, and have the least amount of problems with screen reflection.
The three tablets and their lcd screens all functioned well with the Nook and Kindle apps (I converted both Nooks to full Android units). The biggest problem with them was reflection even with the best anti-glare screen protectors I could find. In brightly lit situations it was always awkward to try and find a comfortable angle that minimized reflections while viewing the screen. Of the three (I use the gPad for everyday use other than ebook reading) the "Goldilocks" screen size was the Nook HD+ at 8.9 inches. I still keep that up and running and its primary use now is for graphic novels as the additional .6 inch screen size over the gPad makes reading the word balloon content easier.
My experience with the Kindle DXG really convinced me of the practicality of the e-ink technology for the best overall reading experience. However, its larger size, no touchscreen technology, and no internal lighting were definite drawbacks but reading from it was a real treat.
I began searching in vain for a reliable e-ink device with a screen in the 8-8.9 inch range and recently acquired the Pocketbook 840 Inkpad and am well pleased with the purchase.
It gives me a comfortable screen size (unlike the smaller Kindles and Nooks), e-ink technology, very lengthy battery life, displays both ePub and Mobi equally well, and fits in my original swivel cover for my Nook HD+!
I use it strictly for reading ebooks and sideload all of them from Calibre so I don't use its browser or even its wifi connection.
I did take a serious look at the newer Kindle Voyager but did not want to go back to a 7 inch screen and it is a bit pricey.
Hope all of the above helps.