Dave, I got the 47WX49 a month ago. It looked great out of the box, and then I had it ISF'd and it now looks fantastic! I imagine you've seen the website devoted to it, panny.tv, if not go check it out, lots of tweaks and enthusiastic owners.
The 47WX51 adds a faceshield that you probably don't need or want unless you have small children or big pets.
I think you could pay twice as much and not get a better HDTV.