Slide Over in general is ok but it lacks:
1) open the app that you have open in slide over to change to main app (full screen)
2) search bar
3) deselect apps that you don't want to show in the list of apps that support Slide Over
Keyboard
The general keyboard response is very slow (Apple's keyboard or 3rd party keyboards)
I have to press two times in the search bar or text area to finally get my keyboard to start typing. Do others have this issue? I get this problem with my iPad mini2 running iOS9.
Mail
You can finally attach files other then JPG/video right from the Mail app (instead of starting with another app e.g. Dropbox) to add an attachment from the cloud. Unfortunately the way it does it is so awfull:
1) you have to press in your e-mail text area, scroll to 'add attachment' and then you can select your cloud storage location(s) to grab the file (see also
this Apple video). It would be so much easier to tap a paperclip icon like Spark and CloudMagic can. I love
Spark and i wish they soon launch an iOS9 update with iPad support. For now i will stick to
CloudMagic for iPad. Both still lack features as i've wrote in
this other wiki E-mail topic in the iOS8 recently.
2) you cannot attach multiple files at once from a cloud storage (only 1 by 1)
3) you cannot save multiple files to the cloud at once (now only iCloud support for 1 file at a time)