IOS8 slowed my iPad3 down so much I can't stand using it anymore, and I began to question why I even had one.
While I welcome any attempt by Apple to optimize and improve the user experience in IOS, but I think anything they do will be lost on my iPad because it's hampered by only 1GB RAM and a slow processor.
I've moved on to a MacBook Pro, which does most everything I want my iPad to do, with the additional benefit of being fully OSX and a great productivity enhancer when I'm away from my Mac Pro.
Edit to add: I absolutely welcome any IOS optimization improvements on my iPhone 6, which I plan on keeping for a long time.
IOS 8 runs great on my iPad 3. Nice try.