Failure to open apps on multiple occasions, ebay almost never opens.
Doesn't maintain timecode if you leave a song/video
Slow transitions to open apps
Sending a message often glitches and shows as having sent 3 temporarily, still having sent one.
Buttons often fail(ones outside of the keyboard(the new text ones))
Multitasking doesn't close apps always, even when they say they have been.
Wifi was pretty temperamental too which was annoying as fuck.
Bringing up the control centre happened too often when I was scrolling(probably about 60/70% of the way down the screen, must be a glitch)
Although there's a huge amount of improvements in every way, I just need something that works, can't wait till it's stable, so many timesaving things.