Brad said that zazen is boring. He was not wrong.
But, I have my opinion here,
Zazen is not something boring at all. But, why some times we feel bored about it. You feel bored because when you sit, your mind is still wanting something more. You think something is more interesting outside there. That's why, no wonder, you got bored. Sawaki Kodo said "deluded person sit on zazen".
But, it's ok... Just let "the boring mind" go... Don't be disturbed by it. Just sit. Cast off the body and mind.