The more the better of course, I for one would watch upto 3-4 hours, as not everything, but some of the information that is being said in these streams, you simply can’t find them anywhere else period. Though considering lots of people want to watch these, I would say a 2 hour (maybe 2.5 hour) session will be nice for each one.
BTW which stream is going to have and ? the may 8th one or maybe both?