My iPad 2 runs reasonably well with iOS 8.1 but I
- set it up as a new device and am very restrictive with background app refresh tasks
- turned of transparency (huge effect)
- turned on reduce motion (minor effect)
I think it's not too bad after all, of course in comparison to its replacement - an Air 2 - it feels like a crawl.
.......what does that do exactly and would I turn it off? What 'huge difference' did it make to your iPad 2?