Hello, here's my two cents (also posted as an IOS Feedback form):
1) no fullscreen video on iPad: this is a significant blunder, and also the single reason why I won't buy the iPad Pro I was so eager to get. Good thing I never upgraded my main iPad (Air 2) to IOS 9, though I've got it on my iPad Air 1.
2) no jump forward and back buttons in landscape on iphone: another blunder, thank God I was able to downgrade my main iPhone (6 Plus) to 8.4.1 on time. I'm not upgrading it to IOS 9 until this is corrected.
3) removal of the old My Podcasts "tiled" layout: the new layouts are too hard to use on an iPhone, esp. due to the small text. The old layout, where each podcast could be displayed using a big square tile instead of only a "list" view, was much easier, esp. when the iphone is not in one's hands (e.g. on a stand, car holder, etc.).
This is very bad design... how did this ever get through focus groups and testers...