Faster USB 3 charging & file transfers are exclusive to Apple's 12.9" iPad Pro
Apple's new USB 3 Lightning accessories offer faster file transfers and battery recharging abilities, but the only Apple device with a USB 3 Lightning port supporting those featuers remains the jumbo-sized 12.9-inch iPad Pro.
Apple has launched a new Lightning to USB 3 Camera Adapter that features a standard USB port with USB 3 speeds. The company also offers a new Lightning to USB-C cable that is compatible with all Lightning-enabled Apple products for syncing and charging.
However, in the description for the camera adapter, Apple notes that USB 3 data speeds are only capable with the iPad Pro. Similarly, the Lightning to USB-C cable will not offer quick charging benefits for any other devices.
That means the new 9.7-inch iPad Pro lacks one key feature of the larger 12.9-inch model: It doesn't have a USB 3 capable Lightning port.
Still, the new Lightning to USB-C cable gives users the ability to plug their iPhone, iPad or otherwise directly into Apple's 12-inch MacBook, which features a single USB-C port for both syncing and charging.

Comments
update: didn't see the last sentence in the description, so 9.7 is USB 2 only
I doubt it. That requires a lot more power, and a much faster bus in the device. It's also a PCI Express 3 only interface.
That's the only thing. But otherwise, it's better than my iPad Pro 12.9" model. It's got the new 12MP camera with the multi hue flash. The bigger color gamet, and that's really a pretty big thing. It's got the ambient light sensors for color adjust, which I assume can be turned off. That's really useful. They both can be bought with 256GB storage.
Overall, this is a pretty good upgrade. Yes, it's too bad the USB 3 isn't there, but there must be some reason, and from what is included, it doesn't seem to be a sales differentiating factor. If anything, from the other features, the 9.7" model is more desirable.
... on second thought. We need a lightning to USB3 CABLE to do that. Not a lightning to USB3 ADAPTER. Oh well..
...painful enough to restore a 128GB device now that's 2/3rds full.
Maybe it's Apple giving the FBI some leverage: "Give us your password, or we'll make you restore your iPad again..."