Just wanted to share what I did with my setup (an RDR HXD870 connected via HDMI to a 2013 KDL42W805A):
I noted some issues in getting the best image from my recorder once I got the new television (I used a KDL32W4000 before). I tried leaving the output from the recorder as per native source (so 576i, before it was set to output at 1080p) and let the TV scaler works to upscale to FULL-HD and the results are much more better. You can check it especially in the sharpness of the recorder menu (pressing the System or Title list buttons)...
Let me know if it is the same for you....
