Is all about content protection. Almost all this is about BLOCKING HI DEF RECORDING. I will now duplicate web content on this here. But I read your post and it is a shame the place that sells you these things will not discuss the limitations of HD recording.
Recently I bought a Sony Bravia W550 and a Sony DVD HDD Recorder HX980.
Unfortunatly, I have found some problems, Please let me know if you can help me.
an important problem is:
while the HX980 is turn on, the TV programs become very noisy.
In the other words, if we want watch TV programs, the recorder HX980 must be turn off, and in this way we can not record any TV programs with a normal quality to recorder!
P.S: I found a not good solution for this problem: If I remove HDMI cable from TV and replace it with a A/V cable for connecting HX980 to TV(Sony Bravia W550), the TV programs become clear without noise.
any way, This solution is not good becuse you can not use from HDMI advantages and so you can not easily record TV programs to recorder .
Please let me know if you are family to this type problem and if you have any idea and comment.