Listening again just now. Have tried setting my player to LPCM and switched back and forth from bitstream and it sounds identical to me. I've got all the DRC and all processing turned off on the amp so I can only assume the DolbyTrueHD is being decoded properly.
It's still bass light to me, especially compared to the stereo mix (which is also DolbyTrueHD so it can't be the container that's a problem). All my speakers are set to large (no sub currently).
Those with full range or larger rear speakers, is there mid/low bass coming from them? My rears are quite tiny, no sure exactly on how low they go but they are very small surround bookshelf speakers and that could be my problem. However, I'm still confused as to why the stereo has real grunt on my system (and my fronts only go down to around 52hz) yet on the surround the bass is there but has lost all power and depth. It's like a ghost of it's former self.
It still sounds great, just wish it had a bit more bite in the lower end. I shall have to revisit it once I upgrade my rears and/or get a sub. I assume if the LFE is quite low mixed, those with active subs can up the volume a tad to compensate?