PCM 2.0 with Prologic II/DTS Neo6 or regular DTS/Dolby 5.1?

[Paganmoon]

Hi,

I've been thinking about this for some time now and was wondering which setting would provide best sound.
I have a PS3 and an "old school" reciever, the sound is passed to the reciever using TOSlink.
Should I set the audio options on the blu-ray movies to uncompressed PCM (where available), effectivly only sending 2.0 PCM sound to the reciever, and let the reciever make that into 5.1 with Prologic II or DTS Neo6, or would it still be prefereble to use the regular DTS or Dolby 5.1 so that the PS3 sends true 5.1 sound?

Question being, which would give the best sound quality.