From an attendee PoV:

• having automatic breakout rooms after each talk to text chat with the speaker was nice
• videos being cut off in the middle of sentences automatically was awkward
• integration of the video widget in the matrix client was a very nice idea but every time I wanted to read a message in another chat it meant losing the talk so I ended up not using the integrated talk widget
• it sometimes felt like I was missing parts of the chat conversations. Not sure if this was matrix dropping messages.