I have HDMI out going to my TV and the audio optical out to my Vizio soundbar. I've had no issues with delay or anything else with any other systems, including Ps3, 360, and regular tv. With the xbox one for some reason if no sound is outputting for a second or more the soundbar disables or something. So for instance if I'm sitting at the home menu where there is no sound, then start moving around (and thusly usually hearing the click) I hear nothing for half a second, and then you volume goes up from 0 to whatever its set at.
So if audio is continuous, such as watching football where the fans cheering is always background noise, there is no issue. But as soon as it gets silent for a second it's like the sound bar turns off and has to turn back on as soon as sound comes back.