As I've just posted in the similar thread in the Sony forum, the following thread in the Kindle forum (which includes a couple of people who've went from Nook/Sony e-readers to the Paperwhite), makes it seem like a no-brainer to upgrade to the front-lit devices: '
New Basic Kindle arrived today'.
That's even with a screen which some people have found issues with, and all but one person wouldn't dream of going back to a non-lit device. It definitely seems to be the way forward.... I'm just waiting to see if either the upcoming Sony or the next gen Paperwhite (or possibly even the Kobo) will be my personal perfect device!