Also, initiating Siri is laggy looking. Notification Center and Control Center on lock screen, pinching to close pictures in App Store, rotating when a picture is being displayed in the App Store, sometimes flipping from picture to picture in the App Store, although it is hit or miss. Notification Center, Control Center, and Siri all lag more when the keyboard is involved. Normal keyboard lags the rotation animation, but the split keyboard is 100% smooth. However, split keyboard causes lag in spotlight, and when simply tapping the address bar. When you fade to the favorites screen and the favorites icons kind of move forward, there is more stuttering with split keyboard, whereas it's usually fine with the normal keyboard. Siri is oddly smooth as it blurs when you do the following:
Wake screen so the lock screen is showing
Slide so you are at the passcode screen
Hold home button down at passcode screen, you automatically will be pushed back to the lock screen and Siri will start. However, the blurring here is very smooth, although it still isn't 100% as the iPhone 5S or iPhone 5 is. It's odd that it is mostly smooth here, because it lags more when you start Siri just when sitting at the lock screen. This all is hard to explain, especially as some people just don't notice stuttering while others do.
I think the algorithms to provide the translucency effect is just highly inefficient, causing the lag. Or the iPad just simply isn't powerful enough to drive the translucency effects perfectly in all situations. I am really hoping it is just software problems. Or we have an iPad 3 situation. Underpowered iPad.
I have seen all of these on my retina mini and on my friends air. Also, my other friends original iPad mini has less lag when it comes to initiating Siri, although it is still there.