PS3 DTS MA & TrueHD Questions

[kiko]

So... If I understand well...

PS3 cannot bitstream DTS HD and Dolby TrueHD ? It can only do it internaly and then send it by Linear PCM (what "PCM" stand for exactly ?) to the decoder ? So what is the use of the Bitstream option in the PS3 if it can't bitstream things ? Only for basic DD5.1 and DTS ? And why the PS3 can't bitstream higher codec ?

And can the difference between bitstream or PCM sound of the same codec be as psychological as the difference between VC-1 and AVC ? Some people think one is better than the other because of some ideas, but in fact, it's the same thing and the difference is only psychological ?

And sound like PCM, DTS HD and Dolby TrueHD can only be sent by HDMI, no matter if the sound is decoded by the PS3 or the decoder ? No optical option possible ?

And finaly... What is the difference between PCM sound, DTS HD and Dolby TrueHD on a blu-ray disc ? Wich one is better ? I always tought that PCM at 16 or 24bits was the best sound... is it ?