I bought it because it's the most common and affordable, and I wanted to see how are we going to play in the future.
The Pros: Basically is the most affordable ball that I could find at the moment I purchased it. From the physical point of view the ball has a smoother texture that keeps it more clean, by this, I mean that less dust/sweat sticks to it, also the color is a brighter white that doesn't fade too much.
The Cons: Like many have stated it before the ball is slower, having said that, is better for my style of play since I haven't been able to adjust to the Pro rubbers that I've been using. The slower ball makes it easy to serve, trading spin for better placement on the other side of the table.
Of course the lack of spin and speed will upset the players that like to engage in fast rallies, also the ball is more fragile than the celluloid version, so if you're a heavy hitter you'll be cracking a few more often.
So far I found it easier to play than Stiga optimum 40+, but it doesn't compare to polyballs by Kingnik and XuShaoFa
I just hope in the future for a quality improvement, and a lower price.