golandaz_mi on 4/9/2014
Very close to tenergy 05fx. Although it is marketed as "hard" but compared to other leading rubbers this one is not. Hardness is tiny bit more than Razka 7 soft. Very good for smash, loop and spin. Top sheet is thin and grippy. Huge amount of spin when brushed the ball on a high speed loop. Not suitable for slow game. Has moderately high throw angle.
Update: Is very spin sensitive to incoming spin. As the other reviewer mentioned this rubber is very close to Razka 7, I would Agee with that. R7 is less spin sensitive, would highly recommend using r7 over roundell hard.
riker71 on 6/9/2012
Same topsheet as regular but 5 degrees harder sponge (40 degrees Butterfly scale, weight 47g cut in 2.1mm, 4 grams heavier than regular roundell on same blade. Gives extra power for looping and smashing. Short game is very good. Goes well with Offensive blade. Excellent speed, spin as good as Rakza 7 and much better control [less bouncy than tensors]