How big of a difference is there between the actual quality of the image between the two when upscaling 480i? (Not counting the VP20's add-in card..)

All I need is a decent scaler to upscale my Playstation 2 games to 720P and I'm torn between the two.

I'm not worried about the couple of less frames the add-in card for the VP20 can shave off since I don't really play rhythm games or what not anyway.. I'm just concerned about image quality.. and I'm assuming that either of those scalers will give me a much better quality image than compared to what my Sammy HLT4675S gives me for 480i through component on my PS2 now..