The Paperwhite is clearly superior to all of them. Gruber's points are all extremely nitpicky.
(1) It's not a big deal to move your thumb an inch to tap the screen. The device is so light that I suspect it would be hard to make a button with just the right resistance so that it could be easily pressed while holding it in one hand. But seriously, moving your thumb isn't hard. Gruber also harps on not being able to operate large screen Android phones with one hand. Just use both hands for crying out loud.
(2) The default Caecilia font is great. I think it's beautiful. Gruber loved picking on Droid Sans, but I think that's a great font too.
It's a worthy upgrade to any of the previous e-ink Kindles.