I have an Ipad 2 and as far as I'm concerned any update after 7 causes problems.
Once you have updated there is no going back and don't hold your breath for any help from Apple.
I'm never buying another Apple product again
Do a backup. Make sure all your apps are up to date. Close all apps & notifications. Then update whilst connected to a power supply. Updates are only available for a certain time period. Best to update than not. I have an ipad2 so an oldie now and it still works as it should.
I cannot understand why if you have a gadget of any description why you would not update when it is available and free. The updates are to fix any bugs which if there are any are sorted. My ipad2 is using iOS 9.2.1. I update it straight away when I get notification. Over the years the main updates have improved the machine.
I have been a bit apprehensive on updating because of hearing of others having problems. My granddaughters ipad froze she had a lot of problems but ok now.