It's no contest between the 125v4 and the SVS PB1000 (in ported or sealed mode). The articulation of the 125v4 is absolutely superb! My buddy and I just did a head-to-head. The SVS 1000 certainly goes lower and louder but it is muddy and not as emotionally satisfying. That goes for movies too.

Absolutely superb musicality. So totally enjoyable. It has me scratching my head why I've spent so much money on Axiom sealed subs.

On top of that, the M2 bookshelves put the KEF floor-standers to shame. And no - none of this took any critical listening. He's so pissed! Slowly he's changing everything out to Axiom.

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