KISS I Count
I do not personally know anyone who is using the KISS I. I do know a few people who are using the KISS II and KISS III and are satisfied with them.
All I can add is that in unbiased computer sims, KISS I yielded 70% the net edge of KO (66% of Hi/Lo); the KISS II yielded 94% and 89%; and the KISS III yielded 103% and 97% respectively in a typical six deck game.