I just went back to 7.1.2 from 8.0, and there's a reason for that. I, and many others, are aware of that not all software works perfectly on release. This isn't the case with iOS 8. It is completely under par with what you should expect.
Let's begin with the keyboard. I had problems with this lag, I'm not sure if many others had the same problem. If I wanted to search something in Safari, write a note, or sometimes messages, it would freeze completely for 2-7 seconds. Typed a couple of characters, and it froze. This happened especially when I used backspace. I managed to fix it though. Disabling iCloud Drive seemed to fix it, but this should NOT be necessary.
Secondly, I experienced several crashes when changing settings in the settings app. This happened not just once (I went back and forth from 7.1.2 to 8.0 a little), and exactly the same happened. If you wonder what specifically I was changing, it was the location settings. This was without having any other apps installed, as this usually is one of the first things I do when I set up my phone.
Also, the network speed. Now this was kind of awful, because this was not temporarily like the other two. I noticed this immediately after installing, because I, like many others, install a bunch of apps pretty fast. After installing, which took a looong time, the performance was insanely bad. Just sending a picture on Snapchat took ages. It took up to 10 seconds at worst to send a photo to ONE person. If you've used it, you know the quality is really low, and it shouldn't take more than <1 second after you press send. This performance was very apparent in Safari as well. Pages were loading painfully slow, and when paired with the awful keyboard, it was a total disaster.
This was just some of the problems I found after using the OS for a couple of hours. It should not be like this. Small bugs I can understand, but when core apps and functionality is so insanely bad, there's something very, very wrong.
Imo Apple has become more and more sloppy after iOS 6 was released, when Forstall was fired. Sure, Maps was a disaster, and Forstall had it coming when he acted like he did. But this was not a problem with the OS itself, just one app, with a problem on the server side. iOS itself was fine. And even if Forstall was acting like a dick, he was a damn good engineer.
And by the way, it doesn't matter if it's 1 person or 100 million who find problems, when the majority is finding the same ones.
Edit: I also agree that some are blowing this out of proportion, but this is still way under par.