I have been experimenting between having my Sky Q box connected via AVR (Pioneer LX 303) or direct to TV (LG B8) using ARC. I was doing this to try and eliminate an issue with Sky Q (another story). I ended up noticing two things. First, connecting direct to TV resulted in lip sync issues. Second, connecting via AVR produced a much better sound quality, like night and day better, as well as zero lip sync. I'm at a loss to understand why there should be any difference in SQ, the sound mode was triggering the correct info on AVR display, e.g Atmos when appropriate, using both connection methods. The only thing I can think of, would connecting direct to TV utilise the AVR calibrated settings (MCACC)? If not, then this may explain why it sounds better going via AVR, which definitely does use those settings.