I like this good looking new iOS but I'm having similar problems with usability, bugginess and performance with iOS 7 on my third gen iPad and iPhone 4S.
On the iPad, the OS periodically freezes and reboots. This is a major problem as it is happening about once per day.
On both products typing is laggy as are some of the animations. This continues to be a problem even after I set the parallax effect to reduced motion in the accessibility settings. Apple: it flat out shouldn't take two seconds for the keyboard to pop up when I open the search bar in Safari. This is a basic usability issue and should be corrected ASAP.
Multitasking is also jittery and unreliable with many apps, including Safari. For instance, if I look up directions in the Google Maps app, switch to another app then go back to Google Maps the app will reload and I have to re-input the directions.
Researching the issue, I found many people facing similar problems when multitasking. Apple says that this happens because certain apps are not configured to use the new background app refresh and this is causing them to reload. It recommends turning off background refresh for those apps in settings. I tried this but it failed to prove effective.
I have found similar problems with some Safari tabs. A couple of days ago I was reading an article on my iPhone in a safari tab. Each time I left the tab then went back to it, whether by leaving the app or switching tabs, the tab would refresh. This was especially annoying as the article was very long and I kept having to find my spot.
Another usability issue: the home button no longer functions as a home button while multitasking. When multitasking, a click of the home button returns the user to their previous app. This is a vast departure from the way the previous OS functioned which was, in my mind, the more logical execution.
Lastly, Siri and the new music app.
Music is and always has been an intrinsic feature of the iPhone but the app has been made significantly worse/borderline unusable in iOS's newest iteration.
I have many bones of contention with this mainstay app too numerous to mention but I'll try to explain a couple.
Apple has forced album art down our throats, by removing the option to remove cover art in the artist list. This is a colossal waste of space, especially on the smaller screen of the iPhone, is information poor and leaves my thumbs exhausted from overuse. There should be an option to toggle album art on/off while in the iPhone's vertical display mode.
Second gripe with the new music app. I have all the tracks in my library sorted by genre. I used to be able to easily shuffle by genre. This is no longer possible within the music app. There is a workaround: you can ask Siri to shuffle by genre but I'd prefer having it as part of the app, as it had been since iOS's debut.
Cover flow: the old cover flow mode was useless. The new mode is prettier but still essentially not usable. This is why it's currently useless and how it could be easily fixed. Currently, whenever you flip your iOS device horizontally while in the music app the app will show you every album on the device in alphabetic order. This is essentially useless, as I have said, because I have over 900 albums. However; if the app changed the albums displayed in cover art mode depending on what genre or artist is open in the list view, then this could be a very cool way to relevantly display cover art. For instance, I have about 20 Beatles albums. If I'm in my Beatles section in the artist list view, it would be logical that when I flip my device horizontally only Beatles albums are to be displayed, right?
Siri and the music app. If I am listening to the music app then interrupt it to use Siri to say send a text or ask the time or something, I have grown to expect that once the Siri query has been completed the music app will resume. But this is no longer the case in iOS 7.
All of these issue taken separately represent minor annoyances; but combined they indicate a product that looks rushed to market without the meticulous care and attention to detail we have come to expect of Apple. Here's hoping the company starts to address some of these concerns before adding new features - bells and whistles - to what is, essentially, a beta product.