Having the very normal kinds of minor glitches with a very small percentage of users isn't something that is "widespread". For as long as I can remember, for the last 30+ years, with every company of every computer-type product with software upgrades, there has never been one single time for all those companies and all those products that for a major upgrade that there were never any fixes issued, usually two or three at the minimum. This kind of thing is so normal and predictable that it makes me realize that there are obviously a whole lot of neophytes here ... :-) ...
This is basically nothing in terms of the latger installed user base and in terms of the overall history of computer products.
This article is a bit more realistic ...
iOS 8.1.1 Beta Vs iOS 8.1: Performance Test For Older-Gen Devices
Major new releases of iOS tend to bring with them plenty of complaints of poor performance on older devices, and iOS 8 was no different with regard to how it ran on the iPhone 4s and iPad 2. Neither hardware is getting any younger, and with limited hardware at their disposal both the iPad 2 and iPhone 4s have been found dwindling in the old speed stakes.
Curiously, Apple has very recently released a beta of iOS 8.1.1 to developers that has an interesting line in the release notes. Specifically mentioning the iPad 2 and iPhone 4s by name, Apple says that iOS 8.1.1 improves performance on those devices which will come as wonderful news to those struggling along with them.
The best course of action to take at this moment is time is to simply upgrade your hardware. Software updates might pump life into older hardware for a short moment of time, but eventually we all know that our aging gadgets will eventually give up on us.
In short, it’s time for an upgrade no matter what. After all, who doesn’t like to own newer gadgets, right?
http://www.redmondpie.com/ios-8.1.1-beta-vs-ios-8.1-performance-test-for-older-g en-devices-video/