I only read on my mobile at night because I have a grouch in bed that doesn't like me having the light on. I never really liked the clip-on lights.
I got my PW today so I'm eager to try it out after "lights-out".
Also - even during the day at home, I sometimes sit in my library and read and I find that I have to turn on an extra lamp. It's fine, but it's behind me so I can have some shadowing issues. Also, when it's warm in the house, the lights/lamps just add to the heat. Somehow I don't think the PW will contribute much to the temperature in the house - which is a good thing.
Front-lit technology was the main function I was waiting for to upgrade by Kindle Keyboard. I've only looked at the PW briefly at this stage and I'm wondering if that brightness will still hurt my eyes. I'll have to play around a little with settings and read for a while before I can say one way or another - eg. maybe I'm just better off having the light at lower settings day or night.