Summary: I just got a HD TV and this being my first upconverting DVD player I am satisfied. I am waiting for the big Blue Ray/HD war to work itself out and drop the pricing before I buy. The Onkyo Single Disc HDMI Player DVSP404 has a great picture and my kids can watch all of their old DVD's that get upconverted to 1080i. I also use this as my CD/DVD player tied into my sound system which performs nicely. The HDMI conections are why I bought this device.
Summary: I bought this DVD player to go with my new ONKYO TX-SR604 receiver and 57inch Mitsubishi DLP TV. Using all HDMI connections the picture and sound are very good. I am sure with HD or BlueRay you will get a better picture but until the market makes its mind up on HD DVD players this is a great low-end go between. Really if you are just the average user (which I am) and not a real electronics buff you might not even notice that much of a step down from a true HD player.
Summary: I would love to keep this player since it's really small, looks nice, and works well in just about every way. However, as one person has already written, the picture quality is not the best. I have seen better in this price range. I tried adjusting all the video settings, but I could never get it to look as good as I feel it should.