[SmokeAndMirrors]

I don't believe there is any substantial difference between any of those models in terms of screen toughness or general reliability. They're all well-liked.

All eink ereaders have a delicate screen. I'd strongly advise a cover with a stiff front and back, like the various book-style covers that are out there.

I have a Kobo Touch, which I keep in a cover. I do carry it around in my bag, but I place it between flat surfaces (my tablet case and my folder) so that there is nothing that will cause uneven pressure on either side of it. I've been lugging it around like that for 9 months with no problems.

I suspect that having an ereader with touch might offer a slight advantage, because the screen is a bit recessed into the bezel which offers just that tiny bit more distance between it, and outside force that might press against it. All three of the companies you mention have a touch ereader.

So, it really comes down to which you like best in terms of the user experience and the features. You can give the demo's a whirl someplace like Best Buy.