Dead or Alive 4 maintains the same spirit as the previous games.... which is both good and bad.
The Dead or Alive games center around a fairly nonsensical plot featuring a fighting tournament held regularly by an evil corporation - DOATEC. Most characters in the game have little to do with anything resembling a plot, as seems to be the norm with fighting games. There is a small plethora of fairly stereotypical fighter types - the ninjas, the wrestlers, the school girls, and the madonnas make up this cast.
Graphically, Dead or Alive 4 is impressive, but you'll really only find the big technological leaps in the small details. Leaves fall around your characters as they fight. Cars drive by (and can actually hurt) the fighters. Bystanders take a more prominent role, and seem much more defined than in the past. The character models all look good, but they don't seem like much of a stretch from previous games.
Sound-wise, there are a number of bone-crunching "ouch" moments, but overall, there's nothing really memorable about it. The music is pretty typical fighting-game techno/rock. The voice-overs are all in Japanese, so it makes it hard for an American to really tell how good the work is.
In regards to the gameplay, DOA4 sticks very close to the previous games. The enemy's artificial intelligence can be great or awful. Sometimes the responses feel human and natural - other times, you'll want to bang your head against a wall after the tenth cheap victory. Surprisingly, the game's end boss seems much easier on harder difficulty levels.
You've seen the game modes before. Story, Versus, Team, Survival, Timed., and Online make up the modes. This game is best online, with little lag and a decent interface.
DOA4 is a good game, but the lack in any real movement forward for the series is a huge detriment. At least it's a carbon copy of genuinely good games,. I'd recommend renting this one.