The icon thing I could never understand. Apparently there was a staggering amount of bitching from technogeeks about the previous icons...that they were too realistic or some such nonsense...and that they needed to be more like "symbols" than trying to imitate real life objects. And this is what we get. I honestly don't care too much about it.
One of the big things that did happen with the new OS that actually is a pretty big deal is the auto update feature. With IOS6 any time that an app needed to be updated you would see a red circle notification on the "App Store" icon and then you would have to authorize the update. Like you wouldn't. Like you would rather have that red dot on your screen calling attention to itself every time you hit the home button. So now you don't have to deal with it anymore because all updates happen automatically. That's a bit of a time saver, in my opinion.
A lot of people hate iTunes but I'm not one of them. It plays music. It works well. I don't care about anything else. The new version is much easier for me to see what's playing. It's displayed in a much bigger area with much better contrast. I like that.
So far there is only one thing that I don't like at all about the new OS. When I use certain apps (like TuneIn Radio, and my Olive Tree bible app) every time I turn them on I am presented with a pop up message that tells me:
"Connect to iTunes to Use Push Notifications"
I can't figure out how to get rid of this pop up or how to turn it off. If someone knows how to make that go away I would like to hear about it.
The Safari browser now has an automatic feature that gives a full screen after a few seconds of non-use. So...more real estate for looking at pages on my phone. That's mostly good.
IOS6 had a separate (and universal) search screen. Now the searches happen within each app. That's not exactly a good change. Sometimes I would want to search by a keyword and get results in several different places...email/calendar/contacts, etc. Now I have to remember exactly where it is that I want to find something.
There are more than these things but they are all that come to mind at the moment.