I have the GM with a fresh install on my iPad 3 and the entire OS is sluggish and slow. It takes roughly ~12 seconds to pop a thumbnail up to set a wallpaper and ~8 to ~10 seconds to actually set it.
I'm not sure how this passed Apple performance testing and quality control.
I'm also getting this issue. Besides this and the lag when switching between setting tabs, the rest of the OS seems pretty smooth after i've resetted all settings.
That said, I don't think iPad iOS 7 is ready for prime time though.