I have an iPad Air which continually locks up for 10-20 seconds quite frequently especially when typing since “upgrading” to IOS 8.
Very annoying. But there is no way back to IOS 7x. My iPhone 4S will remain at its pre-IOS 8 level. Why tempt fate?
That lockup was exactly what my iPod Air was doing after the update. . . especially on FreeRepublic. I found it most frequently did the lockup after doing more than two backspaces. . . and that the editor software on FreeRepublic was the biggest offender at doing it. The problem is entirely gone now after iOS 8.1. But there are some things that have made it go away for other iPad users:
Two things to do immediately. First. Do a full restart from forced cold shut off. You force shut off by holding down your home button and the power button simultaneously for ten seconds. . . until the unit screen goes dead black. . . then hold it some more to be sure. Once it is certainly off, this will have cleared some memory caches that don't normally clear in a regular shut down. Then press the power button for a normal restart.
Check and see if you are still having your lock-ups. If not. You've solved the problems. Get the updates to iOS 8.1 and iOS 8.1.1. These may now be a unified single update.
If not, immediately get the updates to iOS 8.1 and 8.1.1 and do the cold restart above, then do the cold restart outlined above. Check for the problem.
If none of this solves the problem, make an appointment with the nearest Genius Bar at an Apple Store. . . you have a distinct hardware problem, not a software problem.
Mine is all good again. Good luck, Jim