I received my 42D64U on Thursday, but was out of town until today. I just got it up and running, hooked up to a Comcast Motorola DVR via component video (I don't have an HDMI connection on my DVR....yet).
I debated long and hard on the purchase of my first HDTV, having read many of the threads on this forum and watching my parents' experience with their Sharp 46D62U. It has some slight horizontal banding, but really not noticeable. As I was getting ready to purchase a set, I saw a great deal on the 42D64U. I pulled the trigger, and am happy to report that there is thus far no banding on the screen, horizontal or vertical. I've paused on some all-white/grey scenes, as well as some all black scenes, and the picture looks great.
Maybe it's beginner's luck, but I won't complain. I knew the Sharp picture quality would be great, since that's what my parents have had since Christmas '06, but I'm pleased to see the slimmer set and thus far excellent picture.
Hope all those who wind up with the 64U family sets enjoy it as much as I have today so far!