Tonight I was watching an episode of the last ship. Towards the last half of the show, the show would randomly (seemingly) pause. When I pressed play, the audio would drop out and the frame rate would increase until the playtime that elapsed during the pause was caught up to.
I could minimize the lag by staying quick on the draw and pressing play. I am not sure if this is the beta of the tvOS app or the server that is the issue.
I am on server version 1.0.0.2261 and tvOS beta version 1.3 (2241).