I own all three and I have to say that EA dissappointed me in the range of moves you have available to your fighters, the fighters feel very similar. The positive is more the realism, submission system and the variety in upgrading your fighter in career mode.
Undisputed 2010 has more fighters, allows your to customize your fighter more, move set and appearance but feels like a WWE game at times. The camp system is great, but the rest of career mode feels like an excel sheet and is very monotonous.
Going back and playing 09 after 10 feels like a joke.
- Bas Rutten is my hero