I've gone through a lot of volleyball shoes, and these are far and away my favorite.  Prior to this I had gone through a few ASICS models.  The Gel Sensei 2 was the last notable shoe I had.  It was durable, but the shoe weighed a lot, and they didn't breathe very well at all.  The Mizunos though are fantastic!  They are super light and well ventilated.  They run a little wider than the ASICS, so I'm not coming home with my feet all torn up after a few hours of play.  People say that the Tornado line is the heavier and more durable shoe, but I'm pretty happy with these as long as they hold up for awhile.