The iPad has in the recess provided on the keyboard a good foothold.
Admittedly, the Case / keyboard weighs a bit, for me is still on the acceptable side. In any case, writing on the iPad is more comfortable - at least in my writing method "brisk 10-finger search system."
I can say nothing about the performance of the built-in battery, have the part just a few days.
The protective function as an envelope (exterior and display) is, in my opinion, well. The iPad4 fits very well into the envelope, has a good grip and is still relatively easy to remove it again. The back of the iPad no longer is protected, for use of the part had to be removed the cover previously used, I can get over. Finally the back of the iPad is also made of aluminum and - in my case - is the part holding an implement.
All in all, especially considering the current top price of not even 18 euros, I can really recommend this part. I would buy it again.