I played 39° hardness. Surprisingly speedy for a highly tacky Chinese rubber. Has a funny clicking sound and crispy feel when hit on the sweet spot. Serving feels like something between Chinese rubbers and non-Chinese ones, because serves are very spiny and more speedy than a traditional Chinese rubber, somewhat reminding me of Razka 7 in this unique combination of spin and speed (and only this characteristic do; make sure that these two are absolutely different). Given that you've grasped the mechanics of looping well, Blue Whale 2 can be a deadly weapon in loops, but I think it's not for a beginner since it still has the "dead" feeling that a Chinese sponge usually do, which means you don't sensitively feel how the ball works in the rubber while you hit it, which wouldn't happen in a soft European or Japanese sponge. And don't think that a softer version can solve this problem. Very heavy, which is another reason why it is not suited for a beginner.