Both look like good boards I'm more worried about customer support and compatibility with my build.
https://pcpartpicker.com/part/asus-motherboard-z170a
https://pcpartpicker.com/part/msi-motherboard-z170kraitgaming
My build:http://pcpartpicker.com/user/Sabre363/saved/mbBnTW
https://pcpartpicker.com/part/asus-motherboard-z170a
https://pcpartpicker.com/part/msi-motherboard-z170kraitgaming
My build:http://pcpartpicker.com/user/Sabre363/saved/mbBnTW