I too heard the Kharma sub,at HE 2005.Sorry,but it was NOT seamless.I heard it on two different days.If you ever heard the magical Lamm 2.1 drive this speaker,in a really good room/set-up,I'd find it hard to believe any "music lover" could feel the sub was an improvement.Just my opinion,and remember these companies want to sell product.BTW,I have heard the sub on the Midi Ex,and the result was the same,to me.Maybe it is only my own perspective,so my thoughts should be taken lightly.
Best!