What is the better setting to film in? 4K video at 30fps or 1080p at 120fps I'm using the GoPro Hero 4 Black?

What is the better setting to film in? 4K video at 30fps or 1080p at 120fps I'm using the GoPro Hero 4 Black?

Read more: What is the better setting to film in? 4K video at 30fps or 1080p at 120fps I'm using the GoPro Hero 4 Black?