One would need 1.5 foot deep QRD to get down to 200Hz?

A QRD may not do me any good with a 55" LCD smack dab in the center of the 12 foot speaker width.

I can see the M5s wouldn't interest him unless they wore a leather dress.

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