Wife and I both returned our Paperwhites yesterday.
She is planning to settle on using her Fire HD as her primary reading device. She tends to read while sitting in one place and says the tablet screen does not bother her.
I'm on the fence. I have to admit that it's tempting to go with a Fire HD and have so much flexibility at hand. But I read all over the place and really value light weight and portability.
Once my Paperwhite refund gets processed I'll probably order a K4B. For now I'll get by with the old Kindle keyboard.