PS3 Audio output?

[jcs913]

I am sending the PS3 audio/video through HDMI to my Elite 82vsx(with the LFE firmware update). In the PS3 options, I have the Linear PCM always checked. I know for BD's with PCM and or True HD tracks, this is what needs to be checked so the PS3 decodes the audio track properly and sends it PCM to my receiver. But, what about when I play a regular DVD and use the PS3 for the upscaling. What is the more effect audio output, PCM or Bitstream. The bitstream send the raw signal to the receiver to decode. But doesn't it send the Linear PCM output the same? Does the PS3 decodes the DD 5.1 or DTS ES Matrix/Discrete codecs the same through Linear PCM as if I sent them through Bitstream?

The reason why I bring this up is I notice a small difference when I change from bitstream/PCM on the PS3 on a regular DVD track. I know that I am missing audio when I play a BD on bitstream that has a PCM or TrueHD track. The receiver only says DD on the face when a TrueHD track is playing, because the PS3 has to decode it and send it PCM.
But what about a PCM track? Is it the same audio coming out through PCM or bitstream? The receiver can decode PCM, so can the PS3. What gives?
Sorry about all the questions, but the new science behind all is confusing. And now I hear even the new receivers cannot decode the new codecs, because the BD players cannot send them through bitstream. I guess they can only convert them into PCM and then output them through PCM, kind of like what my PS3 does with the TrueHD track sending it to my 82vsx. That's even more confusing..
I appreciate any responces as clarity is key. As I was rethinking my thought process about buying a new receiver, even though I just got the 82 about 8 months ago.