I will say the original American dub, and the music was good. I hated Kai. I'll always side with the original series. Kai in my humble opinion was crap. Everything was garbage about it.
I didn't care for Kai at all. I just felt it was just an unneeded project or just another product.
Reason why I look at it from this perspective is because Dragon Ball Z, the original already exists and Kai was just cut scenes and the rest of it was copy and paste. I actually enjoyed some of the original's filler content. But as a whole, no. I didn't like Kai one bit.
If they had done what Kai had done back when it was being produced to follow the manga closely instead of adding all that filler. Than I would treat it today as though it were the original. Its just one of those things thats a little bit too late. It seemed really half ass to me more than anything.
If they wanted to do a remake using different artists for the entire series. I'm open to that. But using existing clips and new voice actors? No, that just didn't work for me as a fan. They were going off what already existed to market the original series. I saw Kai nothing more than crappy promotion material and all in all. Garbage. I loathed the new voice acting especially Frieza's terrible voice acting replacement.
The original wasn't broke, so I had no idea why they thought they could fix it. I think Hollywood and some anime studios need to adopt the concept that if its not broke, don't fix it.