Add sub to 802D4s?

I’ve been thinking about adding a sub to my newish B&W 802D4s. They’re driven by a McIntosh 462. I love the tightness and quick response of the speakers, and I love the thump of the bass. I listen to mostly rock, new, old, alternative, and less often to chill, jazz or blues, piano or classical.  I have a friend who is quite knowledgeable that thinks it’s a bad idea, as the speakers are very capable and well balanced, so a sub would not only be superfluous but counterproductive. Any experts here agree, or disagree?