PCM vs bitstream with PS3

[notig]

I know this has probably been asked a bunch of times.. And I have read through the threads but I am still slightly confused about this. Can someone correct me?

For PCM which is uncompressed audio... there is no decoding involved therefore it won't make a difference whether you send it via bitstream or LPCM over HDMI from the PS3 to your receiver right?

For codecs which do have to be decoded such as TrueHD... you have to send it as LPCM and not bit stream because the ps3 does not support sending it over bit stream right?

Here is a point of further confusion.. if the ps3 can't send trueHD over bitstream but can send PCM over bit stream that must mean it is not an issue of bandwidth since the uncompressed audio would take up just as much or more space right? What is the issue with this?

I am planning to set up a home theater with a Denon 789 for christmas... if I set it up to decode on the PS3... in what possible situation would I actually want it to bit stream instead? I remember someone mentioning something about DD es or something which is 6 channel audio?