I can give this post that I've been putting up elsewhere ...
There are many users here on this forum who have had some initial problems, and have been able to get their iPads working normally again. I can give you one such solution that seems to work in many cases. With the large majority of users, on the other hand, they have never had any major problems with iOS 8.0.2 (as is the case with me). And in saying that, I'm not talking about some minor glitches, which are small bugs that Apple will fix, but I'm talking about the entire iPad being unusable, as some have reported. There's no way your iPad should be unusable and it doesn't have to be, with the success other people are having.
As I said, there have been many users that have gotten their iPads back to normal from resetting it back to factory default condition. That's what I've been posting in order to help a lot of people here. For anyone else reading this, here are the Apple Support Links for backup and then ... for setting it back to factory default, below.
ALSO ... do know that some people have restored their backups and found out that things slowed down again, which means there is something in the backup that is causing trouble. And many times that could be an app or two that is troublesome. I read the other day that another user had Apple run their special diagnostic software on his iPad and Apple found one particular app that was very bad (causing slowdowns and interaction problems). So, they told him to get rid of the app. When he did, everything returned to normal. So, do realize that even though resetting to factory default helps many people (and it should be done every year anyway, I say ...) that there could be other apps which could cause the trouble, too. And then, as many have reported here, clearing the setting helps at times, too. I've had to clear my network settings a few times, when Safari seemed to be "hanging". And when that happens, it solves that problem. Anyway, there is not just one particular solution that helps for all, but the resetting back to factory default is something everyone should do anyway ... and ... be sure to do your backups, too.
Back up and Restore your iOS Device with iCloud or iTunes
http://support.apple.com/kb/ht1766
iTunes: About iOS Backups
http://support.apple.com/kb/ht4946
ICloud: iCloud Storage Backup and Review
http://support.apple.com/kb/PH12519
Use iTunes to Restore your iOS Device to Factory Settings
http://support.apple.com/kb/ht1414
Also, to see what another user did, read this person's account. There is hope for us all ... :-) ...
keithfrommariettaOct 12, 2014 3:25 PM Re: IPAD2 very slow after IOS 8 upgrade
Re: IPAD2 very slow after IOS 8 upgradein response to pacoKAS
SOLVED: IOS 8 Issues on iPad 2:
I just returned home from a visit to the Genius Bar. Like you and many others, when I upgraded my iPad 2 to IOS 8, it became practically unusable. It was VERY slow, lagged whenever trying to to do anything. Lots of screen freezes and apps spontaneously crashing. I was convinced that the processor on the iPad 2 just couldn't handle the new IOS and I went in to see about restoring to IOS 7.
Thankfully, I was hooked up with a very sharp guy at the bar. The problem is not with the OS, it is with it being an *upgraded* OS. He used the analogy of when you had an older Windows computer and how over time (and over upgrades), they just tended to get slower and slower because of all of the garbage that was carried forward in the upgrades. At those times (and if you've ever had a Windows computer, you get this), the only thing that would speed it up would be to wipe the machine and do a fresh install of the current OS and then reload your apps, and the viola, everything would be fast again. Well, it turns out that IOS can suffer the same problems.
THE FIX: FIRST, be sure you have a current iCloud backup of your device. Connect your iPad to a computer that has a clean fresh copy of IOS 8 on iTunes (this is best done with a computer other than the one that you sync your device to because you DO NOT want to restore it from a back up just yet). Ideally, if you do this at an Apple store you'll be assured of the right version there and someone to answer any questions you might have along the way. You then hold the power and home button down to hard-reset the device and continue to hold them down until it reboots into recovery mode. You then follow the instructions on the computer to reinstall the OS on the device (which wipes everything from it and then reinstalls a clean copy of it). Once this is done (which only takes about 15 minutes), your device will reboot and ask you to set it up. Answer the questions about language, location, etc. and continue until it asks you to log into your iTunes account. Once you do that, it will ask if you want to either 1) Set it up as a new device, 2) Restore from iCloud, or 3) Restore from iTunes. Choose (2), restore from iCloud. This will ensure that it brings down "clean" copies of all of your apps and preferences rather than the potentially corrupted ones that might reside in your iTunes backup. That's it! It will take a few hours depending on how much data and apps you have, but I am happy to report that my iPad 2 is now running IOS 8 and it's running as fast as it ever did when it was brand new!
To sum it up, this process 1) Wipes your device and the garbage causing your problems, 2) Loads a clean and bug-free version of IOS 8 to your device, and 3) restores your apps and data so that it looks just like it did before the wipe, with the exception that it works now! :-)
Note also that by following this process you don't have to go through the painful and laborious process of reloading all of your apps, data and/or settings. iCloud takes care of all of that for you.
