I really enjoyed the demo. It felt more like an interactive episode of Dragon Ball Z than any Dragon Ball Z game I've played. It also had some of that One Piece over-the-top-ness of "let's make characters' mouths as wide as we can when they're screaming" which worked.
Then again, I generally like these kinds of games. I loved Heavy Rain and have fond memories of Dragon's Lair. (Okay, I found Shen Mue boring, but I'm not alone there.) Heavy Rain was worth the full admission price I paid for it a few years back, but I'm really not sure I'd want to play the full asking price for Asura's Wrath. I hate to say it, but I'd wait till used copies turn up and I can get it for under $20.