I have a Yamaha RX-V685 connected to this TV via ARC. Whenever I watch anything on the TV’s apps (Netflix, Plex) that uses Dolby Digital or Dolby Digital Plus, audio is very noticeably delayed behind video. I’ve measured this by filming the TV running the same video several times, with and without Dolby Digital, (and from several sources) and then comparing the waveforms in editing software. The delay for Dolby Digital Plus seems to be about 80ms behind video. Since audio is behind video even though all delay settings are set to zero, there is no way to correct this.

Apparently this is a rather well known issue on Samsung’s forums. This makes using any of the TV’s smart features mostly useless if you want decent audio. The review here fails to mention this. Since this is a straight engineering issue and not a subjective matter, it’s something that would fit well in a “pitfalls section” discussed elsewhere here.