I haven't noticed anything different on my Lumia 830.
Things that still annoy me daily:
- The visual bug when skipping tracks in the volume control dialog.
- The visual bug when returning to the apps list upon exiting an app (the background is no longer opaque).
- The screen is still blinking (turning black for a second or so) randomly throughout the day.
- Screen tearing when scrolling around the interface, makes everything look very broken.
- The alarm sounds sometimes play distorted, not all the time, snoozing fixes it most times.
- Rich Capture still fails (it never finishes processing and the resulting image is 720p resolution) when saving photos to an SD card, or when Living Images is enabled.
- Mobile Data sometimes dies and cannot be enabled until a soft reset.
- System apps (phone, messaging, photos, camera...etc) still crash randomly when trying to do simple things, like dial a number.
- Checking an app in 'Battery Saver' and then returning to the list of apps using the battery (still within 'Battery Saver') brings back a list full of duplicate entries, with some apps missing. Exiting and returning to 'Battery Saver' fixes the issue.
- Quiet hours doesn't switch on automatically when it is meant to, sometimes it does, but sometimes it doesn't bother.
My Lumia 550 also still has the same issues (apart from 3, 4 and 6).
I can't imagine Windows 10 Mobile every being ready for older devices, there are just way too many regressions and bugs at this stage. Maybe in 5-6 months it will be ready for the masses.