Hey,...
try not to expect a big difference or development sa picture quality if you buy an upscaling DVD,
I am using the lower model pioneer DV400, and the only difference I see via the HDMI connection is that the color is much richer, the sides of images are smoother and softer, and the relics and artifacts in the background are a bit clearer. I'd say 20 to 30% improvement, using a 42" plasma, I guess, if you are using a 37" baka mas lalong hindi din kapansin pansin...
I guess, if we really want a huge step forward in terms of audio and video quality my friend, BLU-RAY is the only way to go...
Regards,
ABC