Even if there's no scientific research, e-ink doesn't seem a gimmick to me. I find it a pain to read on a laptop, but find a kindle almost as good as a real book. My eyes simply tire a lot faster with an LCD.
As I said, laptops don't have the e-ink resolution. And depending on what you read, it might not even have the same contrast.
So, unless you adjust the brightness and contrast appropriately and have a hi-DPI laptop, e-ink will come on top for reading. There's also the convenience in holding the reader vs using the laptop to read.
So cannot really compare it to a common laptop. To actually compare like to like, compare an e-ink reader with a hi-dpi ("retina") tablet, with the brightness/contrast configured appropriately.
I don't think it's about resolution. I'm comparing a 15'' 1920x1080 laptop screen to my 2nd Gen Kindle. I think it's about brightness. Light-emitting screens make it harder on the eyes to read books. An iPad's screen feels similarly uncomfortable to me. The main benefit of e-ink is that it doesn't emit light and therefore feels almost like a paper book.
Agreed about the ergonomics: it's more comfortable to hold a kindle than a laptop. However, I'm not sure I could replicate the experience with a tablet: I'd have to lower brightness a lot, increase contrast, and shine a light on it, at which point LCDs stop being comfortable to read.
While I totally agree that brightness is a very important factor, there is another very significant one, front surface reflection. See more in my comment here: https://news.ycombinator.com/item?id=8124039
However, in my experience, resolution matters too. I increased the font-size on my monitor and saw a clear impact on readability.
