Another point of comparison among Kindle Keyboard, Kindle Fire, and Kindle Touch is the use of hyperlinks. Hyperlinks are especially important in Bibles and Bible Study materials for reading a footnote, a cross-reference in the Bible, a dictionary entry, etc.
It is awkward to navigate to any specific hyperlink (unless it is at the top or the bottom of the page) on Kindle Keyboard with its 5-way controller. A touchscreen and hyperlinks are meant to be together. However, a 5-way controller is the pinacle of precision. You know exactly which link you click instead of fishing for it on a touchscreen with big fingers. Also, when you use a hyperlink, you typically want to return to the initial location with the help of the “Back” button. Kindle Keyboard wins this one because it has a physical Back button, which can backtrace as many hyperlinks as needed.
Hyperlinks on Kindle Fire are easy to use because of the touchscreen and its fast response time. The drawback with Kindle Fire that I’ve mentioned earlier is the tendency of Fire’s software to “merge” several adjacent hyperlinks so that only the last one works (this happens even when there is whitespace between the links). Although there is no physical Back button, its on-screen equivalent is the next best thing. Once you slightly tap (without any sideways movement) on the screen, the menu with the Back and other buttons appears at the bottom. It persists for as many “Back” traces as needed until another slight tap on the screen.
Kindle Touch is not the best Kindle when it comes to using hyperlinks. Although it has a touchscreen, its response time is slow and not as precise (instead of the hyperlink a menu opens or page turns or a wrong hyperlink is selected). The Back button is not “persistent.” What I mean is that for each use of the Back button you need to: (1) tap at the top of the screen, (2) tap on the back button. If you want to press the Back button twice the number of taps are 4, if you need the Back button three times, then be prepared for 6 taps. Between each tap there is a response lag time. Not a pretty picture. For detailed thoughts about Kindle Touch from my friend Rick Mansfield, see his post.
P.S. Although it has nothing to do with Kindles, I have some observations about using hyperlinks on Nook Color. Its Back button appears on the screen for exactly 5 seconds after you follow a hyperlink. If you miss that window, you are out of luck! Interestingly, the Nook for Android software has an almost non-disappearing Back button (it disappears if you turn a page). It also lasts for one use only (only the last hyperlink jump can be back-traced.) Am I missing something? BTW, it’s strange to see the Nook for Android on my Kindle Fire.