I've been playing this game like a crazy person. I love it. I think it will give Fight Night Round 4 a run for it's money. The techniques, the striking, everything it awesome.
And I don't even like (or follow) MMA or UFC. Go figure. Anyone else?
The mechanics are perfect. You need to practice all facets of the match to be successful. I was an excellent striker at first, but the CPU started taking me to the ground (where I'd be killed) so I started working that out too.
The physics based damage system is phenomenal. Lean into a hook or a mean kick, and best believe your fight is over. Seeing punches miss because of an animation that the other guy executed for doing a move is the coolest thing ever. The CPU is relentless and plays very much off your style. If you tend to throw a lot of jabs, it'll learn and counter it.