Already did a clean install. It helped a tiny bit for a few days, but it's still pretty awful. The keyboard lags and Safari is almost unusable.
I don't expect an older device to be perfect forever, but it bothers me that they keep rolling out OS updates when the older hardware obviously cannot handle it. It's a selling point but in my mind it's actually a strike against Apple devices. I know if I buy an Android tablet that I will be able to somehow roll back the software to an earlier version, even if it's difficult.