Lol go to your home screen, slide down for spotlight and turn the iPad. You will see what he means immediately. Or you could always go to any website, click on the URL bar, SPLIT THE KEYBOARD, and slide up for control center, or do anything. Multitasking gestures lag horrendously here, Notification Center, starting Siri, anything you can think of. For me, typing sight he split keyboard at all is horrible. The text input is way behind the keystrokes, it's really really slow and just bad. And it's not my device or his specifically, it's everybodies iPad mini 2, 3, or air. Observed it on every A7 iPad.
Despite all this I still love my iPad mini 2 somehow. Such a perfect size for content of any kind.