My initial thought was:
A bass reflex box emphasizes the midrange too, because of resonance. It emphasizes the midrange more so than a TL.
A low pass notch filter (one inductor and one resistor in parallel as a unit, and the unit in series with the driver) will allow for a HIGHER resistor value without losing clarity, since the midrange is getting emphasized in the BR box.
Of course, a higher resistor would lead to MORE bass.

So, for a given driver, the differential effect of a low pass notch filter will be greater for a well designed BR box, than for a well designed TL box.

I understand that the BR may not emphasize all frequencies equally, and a TL may be a bit less colored, but put that aside for a while.

What do you all think?
-akhilesh