DBZ Kai was something I had to watch and after hearing it was an edited version of the original DBZ I was like "Ok, let me see what it is" And I have to say I am glad for it. I can see all the major arcs in condensed form (159 episodes without all the filler episodes that brought the original Z to 291 episodes. While I enjoyed watching Z, the filler episodes and long drawn out fights really made me think of some of those as background noise
It basically has all the good parts, and I enjoy watching it because it's like getting the best of the show. Some of the colors have been softened and I do believe the voice cast has changed partway but I haven't noticed a huge difference so far (80 episodes in)
I hope you truly enjoy this version of DBZ as it is the best and most concise version of the series