Is Mid-Autumn Festival a good or bad time to travel? (crowded places, booked hotels, etc)

Hi! I am traveling to China for 3 weeks and still haven't decided on the dates (September or Oct for sure). I would like to see the Mid-Autumn Festival but am afraid to go on this date and have problems booking or getting a train ticket, hotel, etc.
Is everything as crowded as it is on Golden week? Also, could someone tell me the exact days the golden week will be in effect (counting previous and after days) so I can plan on going on more quiet days... MANY THANKS!