Of all Dragon Ball series, Dragon Ball Kai is probably the second or first most disliked (DBGT seems to most if not all negative feedback) plus, it only lived from 2009 to 2011 and lastly, the music scandal did not help it at all.
If I were to suggest someone to watch Dragon Ball Z or Dragon Ball Kai, I'd probably suggest DBZ since it covers the whole manga (Saiyan to Buu), but Kai with the original score is a pretty good alternative too.
What was Toei Animation thinking when they produced Kai the way they made it.

It truly had a lot of potential (watch Saiyan to Friеza's arc to get an idea of what awesomeness Kai could've been all the way to the end -- with Majin Buu arc which doesn't exist).