Keys will be different than the new macbook air - and it may affect backlighting - in fact probably will. I also wonder how ventilation will suffer since generally speaking - apple vents through the keyboard..
Same thick silicone ones you find on ebay, hard to type on. Back lighting is blocked out, if you want something that feels like a Moshi but don't want to spend $20+, go for a TPU cover on ebay.
Just got this and it fits well but the lettering is misprinted having double letters. I contacted the seller to send me another but haven't heard anything yet. I think it may also cause overheating and leave marks on the screen when the lid is closed.