User blog comment:Master Sima Yi/Assassinews 19-03-'14 – Two Assassin's Creeds for 2014?: Unity and Comet/@comment-3046679-20140621215909/@comment-3046679-20140621224719

Two examples. When you play AC3, look how people's mouths move during interactive conversations. It's random 'mouthopen mouth closed', completely lacking any sort of lipsynch, unlike Altair/Ezio games that had perfect lipsynch during such things. Look at Ezio at the start of Brotherhood when he goes "Tell Contessa I look forward to seeing her this evening."

Black Flag was a little better in this regard, because as far as I've seen, most of those were lipsynched properly, but still lack a smooth transition into regular facial expression, leading me to believe they're scripted somehow. Again, this was not an issue on the old engine.