iPhone 6S very slow after upgrading to iOS 11 Recently I upgraded my iPhone 6S to iOS 11 from iOS 10. After upgrading many animations stutter a lot, sometimes screen transition animations are delayed by seconds. When I press and hold on the screen to get the cursor selection magnifying glass there is a delay of about 3 seconds until I see the magnified text. 

Is there any way to improve this other than downgrading iOS?

I'm currently on iOS 11.0.2.

See below for jankiness when pressing back button. There's a few seconds delay for the title to appear. 
https://www.dropbox.com/s/zx5lo22wj4hhbjf/42CDDAD7-103E-4555-8E2D-511D655F2F70.mov?dl=0
The next best thing is to restore the iPhone software. Meaning erase the software and then using iTunes on a computer to restore the software with a refreshed iOS 11.0.2.


Backup iPhone via iCloud (optional but highly recommended)
Plug in iPhone to iTunes and click restore iPhone. iTunes should also automatically backup the iPhone also. - https://support.apple.com/en-ph/HT201252
**Make sure iTunes is up to date and then restore.
Once restore is done you are going to get the hello screen on the iPhone. Set up the iPhone properly then when you get the Apps &amp; Data screen, restore from iCloud backup (unless you chose not to back it up). - https://support.apple.com/en-ph/HT204184
Then your phone should be back up and working with your stuff back on it and the software cleaned up.


Let me know if you have any concerns/questions/issues.