I could be wrong, but my understanding is that speed is as a HOST and not as a device. For iPad to PC/Mac connections, the speed was only USB 2 since the iPad was acting as a device. To some extent, this is a new features at the silicon level as it now supports it as a device not just a host.The iPad Air 4th generation and current iPad Mini use the A14 and A15, respectively, and both support USB 3 speeds (albeit only at 5 Gbps).