Here's my $.02 on this. I have my TV and HR20's set to Native On. Why? Because you see the picture exactly as it is sent to you from DirecTV. No upconverting downconverting etc. Think of it like a paper copying (Xerox) machine. You can take that paper and copy it, but it will never be the original. When you let a $200 DVR upconvert or downconvert your signal, it will not be as good as the original. There will be artifacts, and symptoms, whether you can see them or not. The best example I can think of is converting a 720p to 1080i or vice versa. When you convert a 1280x720 picture to 1920x1080, there is going to some type of undesirable artifact. You cannot convert these two resolutions using a 1:1 pixel ratio so there has to be some distortion in the picture. Now given, I do work at a television station and am an audio and video purist, but to each his/her own. The only argument I could give for not using native is the time it takes the DVR and TV to switch between resolutions. However, for the purity of the picture, I can live with this, so I keep Native On.