It is not Dolby TrueHD 7.1 per se. I have never had trouble with that in itself, but I haven't gotten around to playing Total Recall (2012) with it's 5.1 prob...but have never had probs (like bitstream audio dropouts) with lots of the titles others have. Denon AVRs, nothing special. I am audio-picky, I would notice a gnat's fart if it shouldn't be there.
IME the most likely probs are when there's Dolby TrueHD (5.1 too) with seamless
branching; that's usually the problem with these Mediatek chipsets. Three of my BDPs have Mediatek chipsets, IOW all except the PS3. Speaking as an electronics engineer, I have never like Mediatek going back many years (they "randomly" support or don't support problems with their chipsets, fixable ones that only they can do though), but what you gonna do?
FWIW, to the person who commented above about my last comment: I
wasn't whinging about lack of FW updates for the 83, merely stating the facts about the PS3. No need to defend Oppo so staunchly, unless you feel they need
to be defended? Do they? For what? I could criticise Oppo for hours if I wanted to, but not about FW updates though (I wouldn't mind some...). To keep it short: Oppo, stick to what you do well, and that is disc players. You are an amateur at the other stuff. Truly "fussy" people don't buy stuff just because it says Oppo, they already know who does what well. And for Oppo, that was playing discs.