I have two iPhone 5s's. The performance is pretty good on iOS 9 and imo is better than iOS 8.Not 6 year old iPhone 3G.
A 2 year old iPhone 5S which ran flawlessly on iOS 8 started to stutter randomly on iOS 9 with decrease in general performance.
Don't exaggerate. It's not even funny. I wish Apple loses so badly that this sets an ideal example before every other companies. Software upgrade must enhance existing hardware to call it update or upgrade. It must not be used as a tool to cripple devices to force common people to buy latest model.
While no one can predict the outcome, I hope the suit gets tossed.