I have owned 5000's 5500's and currently 6000's in a stereo setup used with Meridian room correction below 200Hz

the 5500's had a tendency to overhang in the bass and are a lot more sensitive to placement than the 6000's with regard to exciting room modes. The 6000's are a much tighter design in the bass and image way better IMHO.

The roll off in the bass that you quoted applies only to non active speakers and have to be rolled off much steeper in order to achieve the bass response that they do for such relatively small enclosures in an active design, as Scotty would say you canny change the laws of physics.

Rgds
Stuart

Linn LP12, Ittok LV11, Arkiv, Linn Kairn as a phono stage, MPmax 221, DSP6000's, WiiM Pro streamer.