What a great product. It looks good, it does it's job perfectly and all at a great price. (MUCH lower than many branded items out there.) It is a clouded TPU plastic, but it looks really smart on your iPad. I can imagine it's pretty protective from bumps and knocks, and it shields the aluminium back from scratches completely. It is also unique in the fact that it covers the whole back of the iPad- even the most popular case makers haven't managed to design a case, which works with the smart cover and also protects all of the corners and sides of your device. Blooming excellent. The smart cover still works well, and the 'ridge' around the face of the device doesnt affect the sleep wake feature. The stand modes still work, although the 'movie viewing' stand position is inclined at a slightly steeper angle, which makes it more difficult to watch- although that would be true for all cases of this nature. That wouldn't put me off buying it though.
One thing to bear in mind, however, is that it is very difficult to get on. It is a challenge. In haste I actually scratched the corner of my iPad, whilst trying to use a spoon to lever the case over the corner. The plastic isn't rigid, but it's hardly as stretchy as silicone. You may need to use some leverage too- just don't use something which'll leave a scratch.
All in all, I'm chuffed. I'd definitely recommend it!