I have the 50" Pioneer 720 display (PDP-5080HD) and Bluray is amazing! It looks a thousand times better than DVD unconverted. It looks better than HD cable for crying out loud (provided you use a decent HDMI cable).
The difference is clear The only reasonable BD players on the market are the PS3 (incredible!!!) and the new PIoneer model arriving in stores soon (not ELITE, price around $500USD).
On pioneer 42 inch 720 plasma, will a blueray player playing blue ray disks look better than playing dvd disks? Can you see the difference?