Yet another person who knows nothing thanks to Atari.
The game was NOT designed by Dimps like Budokai 3 was. Spike created the game. And it's not a Budokai game. The Japanese title of the game is Dragon Ball Z Sparking!. Atari simply used the Budokai label (and incorrectly I might add) just to up sales.
The correct term should've been Tenka'ichi Budokai. Not Budokai Tenkaichi. And even so, the game has nothing to do with the Budokai series Dimps made.
I personally thought it was better but only suffered a problem with length. Once Z Battle Gate is finished, there's really not much to do.