KomStat vs KomStat ll

I've read where people suggest the komstat II over komstat. Is this because of reliability issues or more so performance issues? How much of a difference is it? And what year did they start making the komstat 2. I am looking at purchasing a d37 or d39 or d41. Does this thinking apply to all 3 of these models?

KomStat vs KomStat ll