Faster and more responsive.
The apps in iOS 9 now take advantage of Metal, making more efficient use of the CPU and GPU to deliver faster scrolling, smoother animation, and better overall performance. Email, messages, web pages, and PDFs render faster. And multitasking features on iPad feel fluid and natural.
Maybe you didn't hear it but they'll let you read it here. It's towards the bottom.
http://www.apple.com/ios/whats-new/
I guess they never said iOS 9 was faster. Just the apps. Lol
I have noticed the Facebook app seems faster on iOS 9.