I am looking at getting the LG 37" 720p model 37LC7D, I'm space constrained so that's what will fit in my armoire.

I have a Sony 300 disc DVD changer (DVP-CX870, circa 2001) I don't want to scrap, it has component hookups but no up-conversion, so I'm looking at either a new Sony single disc (DVP-NS75H) or another multi-disc (DVP-CX995V.)

With the 37" screen and 720p will I:

1. see much improvement with the up-conversion?

2. if I do get the new player with up-conversion, will I see much improvement using HDMI over component video cables?

These may be neophyte questions but I want a better idea before I jump off the deep-end. I was at Circuit City and saw a difference between the two, but that was on a Vizio 50" plasma, not the set I am looking at