Better to let receiver downmix or have PS3 downmix?

[zor]

I have a 5.0 speaker setup (I may add a sub one day but not anytime soon) and I am pleased that my receiver (Sony STR DG820) is able to downmix 7.1 signals to 5.0 (and do any other kind of downmixing). So when playing a BD on my PS3, I can have it output 7.1 and the receiver will downmix to 5.0 for me. Is that optimal or should I have the PS3 do its own downmixing to 5.1 (for 7.1 tracks) and then have the receiver downmix from 5.1 to 5.0?

I guess I could just try out both and see which is better but was wondering if you guys had any knowledge or experience. TY

PS Neural THX rocks! Try it out.