UltraDavid annoyed me greatly when he was still new. His problem originally was the trap that most commentators fall into, which is talking too much about petty plays, and pretending to be excited about each little detail. It leads to a lot of repeating vocabulary and superficial analysis, and there's this rising pitch to their voice which you can tell is really forced. Agreeing with their partner and then repeating what they said, and falling back on extremely vague generalities -- also signs of an idiot.
But I don't know what happened, because he's very comfortable with himself now and I like him and Chen on stream more than most others. All of the best commentators are like this, relaxed and simply happy to be watching the games. It's nice to hear a real person talk instead of a guy who treats it like a by-the-book "i have to be talking every second or they will be bored" kind of job. I guess it was just nerves, or thinking he had something to prove.