Here's the list of the most annoying issues that affect me since updating my iPad 2 64GB w/Cellular iPad to IOS 8:
EXTREMELY SLOW - When opening apps, or switching between them - We are talking just the built-in apps. Mail, Safari, Settings....
Extremely slow Wi-Fi AND broadband. The Wi-Fi is the worst though. Horrible. Page load times are 2 to 4x slower than my wife's iPad.
Battery life reduced by at least 25%. Used to make it all day long, now I am having to plug it in.
Heat - It is working so hard that the processor is heating up. That can't be healthy for it, and surely the majority of the power issues stem from this.
Copy/Paste not functioning correctly between browser windows. Oh this is frustrating. I just want to paste the URL of one website I am on to Facebook, for instance. Even though I COPY, it's pasting in info I clipped a earlier in the day to one browser tab, but if I open another one, it will paste the correct information. You never know what you are going to get.
Cannot post a photo to facebook by hitting the camera icon when leaving a reply or making a post (using web browser version)... It starts the upload, then just stops. I *CAN* go to photos, then SHARE it to facebook, but that doesn't allow me to post a photo along with a reply.
Multiple app crashes per day. This I can deal with. It's nothing new, it's just more frequent. Safari and Mail seem to be the major culprits. It wouldn't be so bad except it takes 2-4 seconds to reopen the crashed app. Sometimes as much as 10 seconds.
And that's just the annoying ones....