I have done an A-B comparison of the K2 model's in my store. I absolutely love the 9800se and what they are all about, But to my suprise when the 9900's arrived and I did the A-B the 9900's just outperformed the 9800's by quite a bit in all aspect's. Low frequency response was much nicer and with the 4inch midrange just seemed to handle the transients much nicer. I am now in the K2 9900's camp and believe at it's price it is just a brilliant loudspeaker. Jazz, classical,Rock, any type of music is just superb and the new cabinet design is amazing of course because it is a mini Everest basically.