Also note that 64-bit memory bus is on the iPad Air, compared to the memory bus of 128-bit on A6X iPad 4. The iPad Air GPU comes from the Rouge part of PowerVR G6430 by Imagination Technologies, estimated to clock at 450 Mhz.
At the end of the day, Apple wasn’t joking about the device being two times faster, so it becomes the faster iPad in CPU and GPU processing in the market to date. Also, it is the same GPU/CPU power as on the iPhone 5s, which enjoys the same A7 processor. It’s only a matter of time before A7 chip strategy is deployed across all Apple products (perhaps Apple TV devices are next).