Ipad2 very slow after iOS 9 upgrade

I Have an iPad 2 which was working perfectly fine before I upgraded it to iOS 9. However after upgrade it has become ridiculously slow (almost useless)

I Have tried all the possible fixes /solutions but still the same Have also tried to completely reset factor settings and restored the iPad using iTunes with my of but again all in vain.

TO be honest I am really annoyed with Apple - their devices should'nt accept an upgrade if the new upgrade can not be handled by that device. And if the device says new upgrade is compatible and it allows you to upgrade then their should be no performance issue whatsoever.

Another annoying thing is apple doesn't allow to downgrade the iOS. That doesn't make sense - why would you not allow the downgrade - for me that's a restriction on freedom of choice of end users. This should be a legal issue to be honest.

now I can't downgrade to previous iOS version, nor can I use my iPad on this new iOS due to severe slowness.

will really appreciate any help from the community members - or from Apple 'Genius' group.

Thanks.