One thing I can say, Omega IV, the edges chip without you catching the edge. It does not affect play and it does not matter but they chip. Sigma II, the edges do not chip unless you do something to them. Sigma II is slower than Omega IV but is really good for spin and control. Omega V does not chip either. Omega V has the control of Sigma II and the speed of Omega IV.
Omega IV feels like a step down from Sigma II even though Omega IV is faster. Omega V feels like a step up from Sigma II.
Omega IV: A lot of spin, a lot of speed, the topsheet is really reactive to incoming spin so you have to get used to it a little. The sponge is a little dense and makes it a little harder to feel the ball than with Sigma II or Omega V. But this is an excellent rubber.
Sigma II: A lot of spin, not as much speed, and the topsheet is not reactive to incoming spin so you have a TON of control. The sponge is not as dense as Omega IV so you feel the ball way better and there is much more click sound when you dig into the ball when you loop.
Omega V: Really plays a lot like Sigma II but it is way faster. So the power of the Omega rubbers and the control of the Sigma II. Not responsive to incoming spin but you can generate a lot of spin. The sponge allows you to feel the ball and you get that nice click sound when you dig into the ball on a loop.
Vega: I never really played with it a lot. But it is a good rubber. It is a little toned down from any of the three above. I got a friend to use Vega Europe for her backhand because she had some control issues with the rubber she was using and it helped her backhand improve dramatically. It does not feel like it is that much different in class than the three listed above. But it is more control and more beginner friendly without the higher gears. But I know pro players who use and swear by the Vega Pro and Europe rubbers.
