Which will receive fewer visitors, Badaling or Mutianyu?

My family want to climb the Great Wall of China this coming May Day holiday. But I was told by my Chinese friend that the Badaling section will be crowded and it may be a little dangerous for little kids, so she recommend Mutianyu, which will receive fewer visitors than Badaling. What do you think, do you think Mutinyu will be better? Any reply appreciated.