There is about five reasons that probably will prevent you from installing iOS 8 once it release..
Of course it all depends on your choice, no one can force you to do anything you don’t want..
1) Many of your favourite apps may break
Just like any new iOS Apple release, most of your favourite apps many crash when launching it on the new iOS 8, it takes a period of time until the developers work on updating their apps to support the new iOS 8 software..
For example: We’ve heard several reports that popular apps like Skype were crashing quite a lot on iOS 8 GM, which is likely to be same build as the public release. Users are reporting that Whatsapp is draining battery.
2) You’ll Lose your jailbreak
One of the most major reasons that you must know is that once you download the new iOS 8 on your iPhone, you will lose your untethered jailbreak which means you will no longer enjoy the cool jailbreak tweaks, jailbreak themes and etc….
Probably Pangu team will be working on updating Pangu jailbreak tool to support iOS 8, but it will take a long time until finding a hole inside the new system.
3) You have an older device and are concerned about performance
4) Bugs got you worried — you’d rather wait and make sure iOS 8 is stable
If you need your device to work without glitches or unexpected errors, then you may want to wait for iOS 8 to get a few updates under its belt before you make the switch. Not surprisingly, Apple is already working on them. Yes, iOS 8 has been undergoing revisions for a few months during the beta period, but there undoubtedly are bugs that won’t rear their ugly head until the public starts using the release. If you don’t want to be a testing ground for Apple, then be patient and enjoy your stable iOS 7 device.
Let me know what you decide in the comments below.
[Thanks iPhoneHacks]