My 12.9” Pro was sometimes unresponsive with iOS 12 but it’s way worse with iOS 13. Doesn’t respond to taps, scrolling not fluid. It’s almost so bad I’m tempted to downgrade to iOS 12 backup. But it’s hard to know if this is a software issue that will be fixed in later betas or if it’s a hardware issue. All I know is it’s darn annoying.