I think I know the answer to this but just checking. I have the A3 and just recently installed an Onkyo SR576 which supports DD+ (over bitstream I guess) and multi channel PCM.
I don't think the A3 outputs DD+ (or for that matter TrueHD) over bitstream - converts to PCM.
So when my A3 is connected to the Onkyo I will never see the DD+ light come on? Pretty sure I am not losing anything since the PCM output is basically the DD+ or TrueHD track converted by the player.
OTOH for DD and DTS the player appears to output bitstream over HDMI since the DD and DTS lights do come on.
I guess the similar situation applies to my PS3. It outputs TrueHD and DTS HD Master as PCM which the SR576 sees as multichannel PCM but there is no difference between that and having the AVR decode those codecs (if it could)