The Kindle Touch lighted case works really well for light in both a darkened or dimmed area, with the convenience of being built in and always on hand. There are significant drawbacks:
1. The cost of the lighted case is quite high.
2. The cases aren't much in the way of colors/options for custom design.
3. The light is a pain to deal with when reading in a reclined position (like in bed).
4. The case adds some weight to the device (though I still easily can hold it in one hand).
Mostly though, I've loved the convenience of having the light when I needed it. When Nook Glow first game out, I was just a little bit envious and wanted that, especially for the even lighting across the screen. I'd definitely be interested in a Kindle device with glow type technology...then I can buy any case I want, while having the convenience of anytime lighting.