Leon -- There is not much difference at all in the performances of KISS III vs. KO. B/J Bluebook II included a 6 deck simulation comparison between the stock KISS III and the Full Matrix KO. KISS had a 0.02% higher EV. KISS however is formatted with a positve IRC, Key count and Pivot. Also, further back in the refinements section of the book, instructions for the ardent user are provided on how to very simply "true fudge" your running count and index numbers for greater accuracy -- and also how to count all deuces as plus a half point rather than half the deuces as one point. Both refinements are performance enhancers that push the performance of KISS III just beyond that of Hi/Lo for the shoe game.
Cass -- Just one slight critique; With KISS III, your count will rise 2 points with each deck that's dealt and with KO, it will rise 4 points.
Shadroch -- Out of curiosity, I'm wondering what your card tags are for your KISS 2.5.