panny 60u vs. 600u

The sales people all say that the difference between these 2 sets is not just in features, but that it has a "better video processor." I haven't been able to see them side by side with the same content, so I can't really tell. I will be hooking up sound through the stereo system, and using an external decoder from Dish Network, so I don't think I need any of the other features. Is the picture really better on the 600? It's quite a bit more $. Thanks. -Dave