I got a 7422D from Costco about a week ago. I noticed a little clouding and banding on a black screen, but it hasn't been bad enough for my family to notice.
I tweaked the picture using Digital Video Essentials. I got the colors pretty good, but there is still too much red (caucasian faces often look like they have a rash and everyone looks like they have on lipstick), so I had to turn the color control down some to compensate. The next step would be to put on a colorimeter and tweak the custom white balance control, in hopes that I could solve the problem that way, but I don't have one of those yet.
Unfortunately, I'm pretty sure that the set is going back. The big problem is that the viewing angle sucks big time (IMHO). The stats claim a pretty wide viewing angle and I didn't notice anything bad in the warehouse, but once I got it home, I found an annoyingly large color shift (wash out) when I was less than 30 degrees off of the perpendicular. This makes the sweet spot way too small for use in my living room. I guess I'm just going to have to trade it in for a plasma set.