this shakes so much, at times it seems hard to stay in control of your games.  The design is smaller than what I expected, it has quite a kick, and the strength that it shakes at seems appropriate for what you hit.  it provides that extra oomph that is not provided when you don't have a jump pak or tremor pak or that Mad Catz pak.  It shakes the most when you cause rapid rumbles or when you are hit in a game.  I would have given it 4 and a half stars, but that was not available, so I put it down to 4 stars.  However, this is highly reccomended by me