It can't replace Budokai 3 but it still is one of the best DBZ games.
The Good
Feels like the anime, the characters look amazing, tons of characters to unlock, tons of other things to unlock, once you get the gameplay mechanics it becomes very addictive and you get a feeling of great accomplishment.
The Bad
The combos are dull, the characters have few moves that all look very similar, gameplay can get a bit repetitive, moderate learning curve, game cutscenes are pretty bad, a few minor glitches, the music is bad (no awesome japansese soundtack!).
Like I said, this game and budokai are 3 are very different games. If you are a fan of the old budokai games, keep them because tenkaichi does not replace them. I am still playing both because each one has its pros and flaws. Overall, this game is really fun and worth the wait, and I'm sure that if they make a sequel it will be incredibly amazing if they listen to what gamers want. If you are a DBZ fan, this game is definately for you and if you are just a fighting game fan, be patient and learn the mechanics and it will grow on you and you will love having this game.