The rakza z is faster than Vega China. It is also softer than XVC having a 50 degree sponge while XVC has 54 degrees. XVC is like a boosted H3 in some areas.
O7 ying is harder but slower than Hyper or Tour. There are times the hard sponge of the Ying will have this ridiculous arc when spinning the ball but is more controllable than Hyper or Tour. I am more of an O7 Asia bh guy.
Short pips are less springy than inverted rubbers. They just look fast because they are used near the table and they contact the ball early or peak of the bounce.