I think even if you like reading books, unless you know you will do it every day for at least a year or two, to get your money's worth, you're probably better off with a multi-purpose device that you can use for a lot of other stuff, too.
For me, I got used to the refresh flash and it doesn't bother me in the slightest or disrupt my reading. I don't really see the need for a page turn metaphor. The fact the next/previous buttons are right where I'm holding the device is a huge plus in my mind. Devices where you need to swipe the screen to turn a page seem to be missing out on the huge advantage.
The one thing which I absolutely needed to learn how to hack was the margin size. It struck me of a waste of space to have a 20mm margin on the screen. I found a guide to edit a config file on the device and changed to 5mm margin and love it.
That being said, both the Kindle Fire and iPad 2 we have are inside devices only. When going on trips its the Kindle that is always packed with the question of, are we taking the iPad? Oh, yeah, kids want to play Angry Birds.
e-ink just cannot be beat outdoors, I haven't found one active display that works well in that environment.