Iidx rips hard. The learning curve is more of a learning cliff-face, but the feeling of competence is really unlike any of the other rhythm games I've played. It feels like it spreads your focus out further, rather than demanding extreme focus on two, or four fingers, you need to interpret and execute with 7-8. Deeply deeply satisfying when you feel in the zone. Even the "gimmick" of scratching feels great a lot sooner than sound voltex's lazers ever have for me.