Here's the feedback I sent to Apple at http://apple.com/feedback :
Some feedback on the iOS 7.0 user experience. I'm a UX designer and software developer.
(1) Animations are making me nauseous, inducing vertigo, slowing my workflow, and distracting from the overall user experience. Judging by the forums and press, I am not alone. Please provide a way to disable animation.
(2) Thin black text on bright white background is difficult to read, fatiguing, and after awhile results in the allusion that the screen is vibrating. It's a poor default choice. You've ignored years of UX research that points to fatigue caused by black-on-white. Please provide a way to change this theme.
(3) The default font is a poor choice, it's too thin and delicate for a small device like a phone. Workarounds I've found are all in "Accessibility" settings (bold font, larger font, higher contrast). If people WITHOUT disabilities have to resort to using Accessibility features, you have a serious design problem. (I have excellent vision btw, and I'm having problems with the default settings.)
(4) Gratuitous interface changes are interrupting my workflow. Millions of iOS users are conditioned to 'swipe right' to delete something (eg, an email.) For some reason you changed it to 'swipe left', which I found only by doing a Google search. This and other changes have me wondering... why take something that works so well and change it? You didn't make it better, you just made it different.
(5) Inconsistent interface conventions. For example, in the Mail app: In one place, there is a trash can icon to delete things. In other places there is a "Trash" button.
It's amazing to me that these issues got through your beta testing process. Hopefully you will correct these via a prompt iOS 7.0.1 release.