One of my main reasons for upgrading to an iPad Air 2 last year was the horrible performance of the iPad 2 on iOS 8 (before the point releases). I'm wondering if iOS 9 will be appreciably better. I'm going to be helping a coworker with his iPad 2, which apparently is very laggy (and possibly still on iOS 4 or 5). If so, can you make the jump all the way to 9 and will 9 perform reasonably well on an iPad 2?