?#1, Dedicated LFE input
?#2, Kick @$$ subwoofers
?#3, Huge, bulky heavy speakers that sound awesome, just like the SVS subs. We don't see too many floor speakers with 10s, 12s, or even 15s in them any more.
A very cool idea would be a floor stander based on a PB 13 Ultra. It essentially has a PB 13 Ultra in the bottom of the cabinet, completely sealed off from the rest of the cabinet. Then the upper cabinet houses a 10" woofer, a mid and a tweeter. They weigh about 800 lbs each because they are built like PB 13 ultras from head to toe, and everything just works. You plug it in, hook up your speakers wires, and go. It has a flip switch to take signal from speaker level inputs already powering the rest of the speaker, or a LFE signal to feed the sub portion. This would make it just work for HT or Stereo applications.