Once every six months something inspires me to put a book on the Kindle that I received as a Christmas present two years ago. Then the frustrations begin. In this case, after finding the table of contents I try to use the up-down-joystick-button to navigate the TOC. It's just painfully slow and it's displaying definitions for every word I happen to be on (it starts off showing me the definition for "Table" in Table of Contents). The lag between pressing the button and the cursor actually moving is too frustrating for me to even use the damn device.
Perhaps the "two years old" is my problem and I just need a newer device but, boy, I just can't get myself to use this thing with any consistency.
I read almost twice as many books since I got my kindle for Christmas last year. I even prefer reading on the kindle to reading on a pc/tablet or a traditional book.
That said, for reference books, it's worse than the alternatives. I almost exclusively use it for reading books back-to-back (i.e. relying very little on the arrow keys)
I've found that a 10" tablet (a Touchpad in my case, though I imagine the experience with an iPad is equivalent) it pretty tough to beat for reference material. Doesn't have the navigation issues that the eink readers do, but it also allows me to make searchable annotations and highlights as I read.
You could try the kindle app for your computer/phone/tablet. I like reading books on my iPhone on my daily commute and it's quite nice (except for some technical books where the source code formatting is obviously quite bad with the small screen).
I have the current Kindle with joystick-button and although moving the cursor about isn't exactly smooth it moves quickly. The definition thing can be annoying.
Perhaps the "two years old" is my problem and I just need a newer device but, boy, I just can't get myself to use this thing with any consistency.