I like these presentations very much.
But I would definitely change one thing which is:
Don't cur the video when clock rings. Let the presenter finish the sentence first (or the point)
It is not nice first and looks like some download failure thing for some people.
I know it is the whole idea, but they try to talk about something interesting. I want to listen to the end as well... If you don't mind.
Finishing the thought: Stop cutting people off, stop do that, start to do it profesionaly guys!