Okay, whether aluminium foil and aircraft grade aluminium are the same or not, it does not change the fact it will definitely degrade any kind of signal the aluminium is enclosing. Just for the sake of it, I just did a test with a piece of alu foil folded into 4 to make up the thickness I think this case would have for the back piece, and then chuck it on the back of the phone and then fit into an alu bumper case I have:
And then I use some signal monitoring app to see the changes in cellular and wifi signal with and without the case on, here are the results:
As you can see with the alu bumper and alu foil back cover, signals do drop and fluctuate a lot more than normal trying to gain/detect the signal (which will definitely drain battery more too). Wifi test with 17% signal strength lost, and cellular 3G also with 17% signal strength lost.
I'm not against this case at all or any other aluminium case/bumpers, the fact that I own quite a few of these bumpers for my past iPhone 4, and one for Note 2 right now. I also already ordered 2 of this case despite the fact knowing the signals will be degraded and potential additional battery drainage.
Just my little contribution for the people still wondering if metal cases can/cannot affect the signals, the answer is YES it does but to a certain extend depends on the thickness and materials used in the case.
Let's just hope the signals aren't too degraded with this case like the test I did, or else I'm gonna have a bad time ^^!!
