I also expect the M5HP to play louder and cleaner. I heard the M5HP starting to complain at 105dBC peaks from 12 feet away. I could drive an M5HP/800v4 to 107dBC peaks at 12 feet away with them crossed to the 800v4 at 80Hz. That's with music.

House of the Rising Sone
Out in the mid or far field
Linearity and mid-woofers are over-rated