Good for you, maybe you didn't care or notice the performance hit much, and that's great for you, but the fact is there was a performance/responsiveness hit, that's a fact and no one here, not even the apologists are disputing. Perhaps it doesn't affect you, but it's there. And it does affect people to varying degrees depending on what device they have.
It's really tiresome that some people here keep defending Apple, what's the point? Does Apple need defense? It seems to me if we all agree there is a performance hit, why not acknowledge it, send feedback to Apple and keep educating other users about the issues so they do the same. The more feedback Apple gets the more chances it'll get addressed.
But why keep defending or making excuses? I guess you don't want people sending feedback to Apple about fixing the stuttering etc?
And by the way, 9.3 so far seems to have addressed a significant part of the performance issues which undeniably confirms there was an issue and Apple fixed it, we don't know if feedback played a role or not, but it might have helped, no?