Got the update about a half an hour ago on the West Coast.
iPad Air 1 previously running iOS 9.2.1 which was ota from 8.3 and ran like a 10 year old device.
9.3 ota build 233 is running smoother compared to 9.2.1 but nothing like iOS 8.3.
No lag in control center dragged up from bottom, notification menu dragged down, or search thing or popped up dragging across empty space on home screen.
I did disable reduce motion prior to ota upgrade and it's still disabled but smoother now. Task switcher somewhat smoother.
Loading safari from scratch not out of memory there is still lag when displaying bookmarks or favorites from initial load.
In bmssm lower idle cpu usage and memory usage present with this ios version.
So far this is a keeper and works better than 9.2.1
Only downside is my net gear genie router app does not work right and has not been updated in awhile. I cannot load network map to display devices connected to router. App problem not iOS.
Anyhow good job apple. I might just buy the new iPhone se and either a mini 4, air 2 instead of iPad Pro 2. Because all that new hardware with smaller battery in iPad Pro 2 is going to eat battery life when there is heavy taxing load on cpu or gpu.