I also noticed that there was very little response to Vanya's tirade/aria in Act 2. When I saw it in its LCT run, there was a huge explosion of applause. In the video, it was quite more polite.
That being said, I wondered what I had liked about the play in the first place. The Cassandra character in particular seemed worse than ever and felt drafted from another play. Totally forgot it had won a Best Play Tony.