Branson for sure busier.. with est 18-20,000 more people in town for the event.. more traffic, shows are busier, eating place are busy and so on...
However most of these people stay in town and dont flow to SDC, so traffic there is normal for the season.. almost the last week off from school. last minute trips, so there is stuff going on there too.
Main thing is the additional traffic in Branson, starts about noon,, and stay bad until late evening..
good luck, enjoy..