17yo, Chinese penholder, inspiration on Xu Xin style. I practice 3x week for 4h30min and 3x week for 2h30, physical training 2x week. Saying this for you understand the people who reviewing this rubber. Using this about 2 months on FH on a Hurricane HAO, 5ply all wood, very thin and flexible. I will talk about the general first, then some specific points.About hardness:I believe versions 40 and 41 compare to the hardness of the Gewo Nexxus EL PRO 53 Hard. But the 39deg version is practically a 50deg on the European scale, if I compare my Skyline with my GoldArc 8 50deg, it has the same hardness.About speed: this is definitely not slow, or super slow, it just doesn't "jump" like European rubbers. It's not bouncy, it doesn't have its own speed and mechanics like most tensioned rubbers. But that's not exactly a problem, go ahead.So let's talk about this rubber.The most important part here is learning to spin the ball by brushing it, not hitting it, you can spin the ball simply by hitting it with European rubbers, not with this one.Be aware that if you're looking at this rubber, you're going to need to focus a lot on learning how to brush the ball. And now comes the part that I put as con and as pro. It depends on your own strength, that means it doesn't have a strength limit, if you spin correctly according to the force you put in, the ball goes in, and why spin correctly? Because if you hit hard without spinning it will certainly be a flat hit and the ball will go out. That's the pro, the rubber really converts your power and the ball can go really strong.But what's the con? Remember I said that rubber isn't super slow? So, now is where that comes in. If you don't put your strength but put spin on it, it will go relatively well with good positioning, it won't go strong or fast, but it will go relatively well. And you start to settle for that, with a "mushy" ball. It goes linear, it goes with a lot of spin, it doesn't go slow, but it's not fast and it's not strong, it's just another ball on the table.And well, to have a strong ball, you need to give your 100% all the time. If you give less than that, she will be much weaker. You MUST have good footwork, you MUST have good weight transfer. And you need GOOD technique, you need to know the right time to do a smaller movement using more forearm and you need to know the right time to do a full stroke using more shoulder and triceps using less forearm snap. And for counters, you MUST do strenght to COUNTER, actually COUNTER THE BALL.Watch a lot of Chinese technique videos, when you go practice, try to practice with a coach as much as possible and focus on your footwork and leg and hip strength. My forehand really jumped after I started using this rubber, I'm not the one saying that, but everyone around me told me that my forehand is actually much stronger and I'm playing much better. Good luck 
