It was a different geometry mostly. Fit mods and styles preferred by many.Just didn't feel it brought anything different that time. B'coz those days I was already superjoyed with the k'fun twins (K-5 and K-mini v3).
You know I’ve been a kayfun enthusiast for years so I know my Kayfuns. I will say this. 90% of the time when I’m vaping my K19 or KM3 or K5 I am thinking they are just as good a vape as the Prime. 100% of the time I am vaping the Prime I have never thought the K19 or KM3 or K5 was better. To me, nothing has ever been a better vape than a Prime.