- The change to logging in makes it much slower to log in,
- all the animations between screens make it appear as if it's slow and clumsy,
- they've changed the default news app from being a list of lots of news from all over the place to being grouped into categories which is less interesting to scroll through,
- and worst of all they've changed the calendar so that it goes translucent with multiple events and shrunk the widget so that it doesn't show the whole day. It's now unreadable all the time and useless in showing me quickly what will be happening later that day.
It's a very niche need I know, but the apple default calendar app used to be able to deal with it.