Got the Blue Sponge in MAX thickness.
This is a solid rubber for a complete beginner who is just learning the basic strokes, how to serve, etc. It is quite slow and the rubber is dead and hard, but this gives it ample control and the tackiness gives it solid spin as well. On a flexible all wood blade this is a great rubber to begin learning how to loop properly, the chinese style.
Unfortunately for players beyond the beginner stage, unless you are into boosting or other gluing methods, this rubber doesn't have the speed you need to play a modern offensive game. It takes a ton of effort to generate reasonable speed during loops, and even third ball attacks run the risk of being blocked back. The tackiness, although fairly high, is still not as high as most DHS rubbers like hurricane and skyline, and there is occasionally some slipage after extended play. Combined with the dead sponge, this means the spin is also not quite as high as you would like for competative play. Shots like lifting underspin pushes and chops require very big and integrated motions that, again, are great for training, but not ideal for performance.
Although the $10 price tag is outstanding and makes the rubber hard not to recommend, this isn't a rubber I would chose for a developed player, or even a developing player. Dishing out a few extra $ for DHS hurricane or skyline will give you all the control this rubber offers, with a lot more speed and spin on almost all shots. It isn't a bad rubber by any means, but there are better options.