I have a Kindle Keyboard and a Nexus 7 with the Kindle app. Lately I've been reading more on the Nexus 7, but when I use the touchscreen to turn pages it has a very high error rate. I usually turn the page by tapping the screen on one side or the other, but as often as not, my tap has a bit of a slide to it, and if that slide goes the wrong way I get the wrong page. It's really very annoying.
(I don't know if the touchscreen Kindles have the same tap/slide interaction; I'm just reporting my experience with the Kindle hardware and software I have.)
It would be much less annoying if I had the option to disable sliding entirely and just respond to taps without regard to any sliding motion. Then I could tap one side of the screen or the other reliably.
But seriously, one side of the screen or the other? Haven't they heard that people hold the Nexus 7 with one hand while reading - and not always the same hand? If I'm holding it with my left hand, it's not easy to get my thumb all the way to the right side to do a tap page flip.
If this worked like the late great FictionWise eReader software, I'd have the option of ignoring all sliding motion and tapping the bottom of the screen for the next page or the top of the screen for the previous page. Then it would work identically with whichever hand I'm holding the device.
Now consider the Kindle Keyboard: Each side has a big next-page and a smaller previous-page button. It's trivial to hold the device with either hand and rest my thumb on the next-page button. I can click that button when I want, without moving my hand at all! No worries about tapping the wrong side of the screen, accidentally sliding the wrong way, or anything. It just works.