DBZ VS KAI (SUB ONLY)

So i hear a lot on internet that Kai sucks..

Can anyone elaborate to me on this?

I enjoyed dbz as kid,but now i watch Kai mainly for rewatch(only sub)(and i found Kai with old dbz soundtracks,cause of some copyright incident)..

So what do i lose and gain when i watch DRAGON BALL KAI SUBBED against DBZ SUBBED..

Please,someone who has experience in both,tell me.(no need to mention dub at all)